Medical Dictionary
Labour
| Labour is the process of passage of the foetus and placenta from the uterus, through the vagina, to be external to the mother. |
Labyrinth
| The labyrinth is a part of the inner ear involved in balance and perception of movement. |
Labyrinthitis
| Labyrinthitis is a balance disorder. It is an inflammatory process affecting the labyrinths that house the vestibular system (which sense changes in head position) of the inner ear. |
Lacrimal glands
| The lacrimal glands are the sites of tear production in the eye. |
Lactate dehydrogenase
| Lactate dehydrogenase is an enzyme that catalyses the conversion of lactate to pyruvate. |
Lactation
Lactation refers to the production and secretion of milk by the mammary glands following pregnancy. The term is often used interchangeably with breastfeeding. |
Lactational Amenorrhoea Method
A method of contraception based on the natural phase of infertility that occurs with breastfeeding shortly after birth. If followed strictly, it can be highly effective as a contraceptive method. However there is a small risk of becoming pregnant if relying solely of breastfeeding, as with all contraceptives. Some of the guidelines of this method includes:
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Lactic acidosis
| Increased acid levels in the plasma due to accumulation of lactic acid. This may be caused by conditions such as heart failure or kidney disease. Lactic acid is released as the end product of glucose metabolism in the absence of oxygen. With elevated blood sugar levels in Type 1 diabetes, lactic acidosis can occur. |
Lactose
| Lactose is a type of sugar found in milk. People with lactose intolerance have difficulty digesting (breaking down) lactose. |
Lactose intolerance
| Lactose intolerance is the inability to digest significant amounts of lactose, the predominant sugar in milk. |
Lactose intolerance test
| The lactose intolerance test involves giving oral lactose (1.0-1.5g/kg body weight). Lactose intolerance patients develop diarrhoea, abdominal bloating and discomfort within 20 to 30 minutes. Blood glucose is measured 60 minutes before the oral lactose is given and 120 minutes after. As a person with lactose intolerance does not digest lactose, the blood glucose level in such a person does not rise more than 20mg/dL above the baseline. |
Lactose-13C-ureide test
| The lactose-[13C]ureide test allows a non-invasive assessment of intestinal transit time. It is based on a similar principle to the hydrogen breath test. The lactose-[13C]ureide test involves ingesting lactose-[13C]ureide. Intestinal bacteria break down the lactose-[13C]ureide and 13CO2 is produced. This is then detected in the patient’s breath. |
Lacto-vegetarian
| A lacto-vegetarian is a vegetarian who includes milk and milk products in their diet. |
Lamictal
| Lamictal is used for the treatment of epilepsy in adults and children. |
Lamisil Cream
Lamisil cream is used in the treatment of these fungal infections:
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Lamisil DermGel
Lamisil DermGel is used to treat fungal infections. Including:
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Lamisil Tablet
Lamisil tablet is used to treat fungal infections. Including:
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Lamitrin
| Lamitrin is used for the treatment of epilepsy in adults and children. |
Lamivudine
| Lamivudine is used in the treatment of HIV Infection in combination with other antiretroviral agents and Chronic Hepatitis B in patients with evidence of hepatitis B virus replication. |
Lamogine
| Lamogine is used for the treatment of epilepsy in adults and children. |
Lancinating pain
| Lancinating pain is the term is used to describe all types of what we experience as ‘sharp' pains this includes jabbing, piercing, knife-like, cutting or stabbing. |
Lanreotide
| A protein which acts to inhibit the release of various growth hormones into the circulation. Lanreotide is used for treatment of acromegaly. |
Lantus (insulin glargine)
| Lantus (insulin glargine) is a long-acting form of the hormone insulin, used to lower blood sugar levels in patients with type 1 or type 2 diabetes mellitus. |
Laparoscopic Surgery
| Laparoscopic surgery, also known as 'key hole' surgery, involves putting a camera and some surgical instruments through small incisions in the body. These allow the surgeon to conduct surgery without the need for large cuts. This generally reduces blood loss and improves recovery. |
Laparoscopy
Laparoscopy is the process of inserting a camera, for the purpose of medical investigations, into the body through small incisions. This enables clinicians to view internal organs including reproductive organs. |
Laparotomy
| Laparotomy ia an abdominal surgical procedure in which access to the abdomen is gained via an incision in the abdominal wall. |
Large cell carcinoma of the lung
| Large cell carcinoma of the lung is a type of lung cancer. The cells of this tumour appear large and abnormal under the microscope. |
Laryngeal oedema
| Laryngeal oedema is where there is an excess accumulation of fluids in the tissues of the larynx. This results in obstruction of air flow and shortness of breath. |
Laryngitis
| Laryngitis is the inflammation of the voice box, larnyx, at the back of the throat, which controls air supplies. |
Laryngospasm
| Laryngospasm: Laryngospasm is the closure of the pathway of the larynx which prevent the air from entering to the lungs. |
Larynx
| The larynx is part of the respiratory system and is often described as our voice box. The larynx acts as a funnel enabling the passage of fresh air down from the outside world into our bodies. |
Laser
| Laser stands for 'Light Amplification by the Stimulated Emission of Radiation'. It is produced in an optical cavity containing a substance. This substance is called a laser medium. The substance can be a gas (eg argon or carbon dioxide - these are commonly used), a liquid (eg dye) or a solid (eg ruby, yttrium-aluminium-garnet). |
Laser Therapy
| Like the name suggests, Laser therapy involves using a laser as a treatment method for different diseases. |
Lasers
| Laser is a device which emits a powerful and localised beam of light. |
LASIK eye surgery
| LASIK (Laser-Assisted in Situ Keratomileusis) is a type of refractive laser eye surgery performed by ophthalmologists for correcting myopia, hyperopia, and astigmatism. |
Lassitude
| Lassitude refers to weakness, weariness, listlessness, exhaustion, lethargy. |
Latex Agglutination Inhibition Test
The latex agglutination inhibition test was an early immunoassay method of pregnancy testing. More about pregnancy testing. |
Laughter Therapy
| Laughter therapy can be used as a psychotherapy. Humour in psychotherapy has shown to have positive consequences on the clients’ mental health. Laughter provides relief for the client and can decrease stress. It has also been shown that laughter has positive physiological effects on the body. |
Laxatives
| Laxatives are foods or substances taken to induce bowel movements or to loosen the stool. |
LDL cholesterol
| Low density lipoprotein (LDL) cholesterol is a type of cholesterol molecule that circulates in the blood. It is often called 'bad' cholesterol because it is a can build up in arteries and contribute to problems like coronary heart disease. LDL-cholesterol lowering drugs may be used to help reduce levels. |
Leaky Gut Syndrome (Intestinal Permeability)
| Leaky gut syndrome is an increase in the permeability of the mucosal layer of the gastrointestinal tract, allowing bacteria, toxins and undigested food particles to pass through and into the bloodstream. |
Learning disability
| A disorder in one or more of the processes in the brain involved in understanding or using written or spoken language. Examples include inability to read, write, spell, speak, or perform mathematical calculations. |
Lennox Gastaut Syndrome
| Lennox-Gastaut Syndrome (LGS) is a severe form of epilepsy which develops in childhood and is characterised by multiple seizures which are typically difficult to control, a specific pattern of brain activity on the electroencephalogram (EEG), and intellectual impairment. |
Lens
| The lens is a biconcave structure suspended from the inner surface of the ciliary body of the eye. The shape of the lens can undergo minor changes in response to tension of the ciliary muscle to allow for proper focussing on objects. |
Lentigo
| A flat dark brown spot found mainly in the elderly, on sun exposed skin. This is a cause of benign melanocytic lesions. |
Leprosy
| Leprosy is a disease affecting the skin which is caused by a bacterial infection. |
Lescol
| Lescol is a brand of medicine that contains fluvastatin as the active ingredient. |
Lesion
| A lesion is an abnormal formation of tissue, for example a cut or an area of tissue which is affected by disease. |
Lethargy
| Lethargy is a general state of tiredness and inactivity. People who are lethargic find it difficult to motivate themselves to perform regular daily tasks. |
Leucocytospermia
A concentration of white blood cells in semen higher than the WHO reference values. More on sperm analysis. |
Leukaemia
Leukaemia is a malignant progressive cancer in which the bone marrow (the blood-forming organ) produces abnormal and immature white blood cells incapable of fighting off infection. Leukaemia is fatal if left untreated. |
Leukocyte (White Blood Cell)
| Leukocytes (also called white blood cells) circulate in the blood and body fluids and are part of the Immune system and come in three types: granulocytes, lymphocytes and monocytes. |
Leukopaenia (Leucopenia)
Leukopaenia refers to a reduced number of white cells (leukocytes) in blood. |
Leukopoiesis
| Leukopoiesis refers to the production of leukocytes or white blood cells of blood. |
Leukotrienes
| Leukotrienes are a type of chemical that is important in the process of inflammation. |
Levemir (Insulin Detemir)
| Levemir is used to treat diabetes type 1 and diabetes type 2. Levemir contains Insulin Detemir which is used to reduce high blood sugar levels in people who have diabetes. |
Levitra
Levitra is a medication used to treat erectile dysfunction in adult men. It can help men who have difficulty achieving and maintaining penile erection. |
Lewy Body Dementia (DLB)
| Dementia with Lewy bodies (DLB) is a neurodegenerative disorder associated with abnormal structures (Lewy bodies) found in certain areas of the brain. In addition to dementia, patients with dementia with Lewy bodies experience hallucinations, motor impairment, and fluctuating alertness. Dementia with Lewy bodies is the second most frequent cause of dementia in older adults. |
L-glutamine
L-glutamine is a type of anti-inflammatory medication that can be used for oral mucositis. |
Libido
Libido is defined as sexual drive, desire or urge. |
Lichenification
| Thickening of the skin with hyperkeratosis caused by chronic inflammation, usually resulting from prolonged scratching or irritation. This is commonly seen in cases of contact dermatitis. |
Lifestyle Drugs
Lifestyle drugs are drugs taken for recreational purposes. They include marijuana, ecstasy, cocaine and alcohol. Recreational drugs are also known as recreational drugs. More about drug abuse (substance abuse). |
Lifestyle treatments for obesity
| Lifestyle Changes are one of the most important treatments for obesity. They produce weight loss by reducing energy intake and increasing energy expenditure via diet and physical activity measures. Lifestyle changes should be part of all weight loss programs and may be used in conjunction with surgical or pharmacological (drug) treatments. |
Lifetime Prevalence
Lifetime prevalence refers to the proportion of people in a population who have experienced a disease at some point in their life. |
Lignocaine
| Lignocaine is a local anaesthetic that stabilises the neuronal membrane and prevents the initiation and transmission of nerve impulses. |
Lignocaine hydrochloride
| Lignocaine hydrochloride is used topically to relieve itching, burning and pain from skin inflammations, and used to numb people in dentistry, and minor surgeries. |
Limbic Lobe
| The limbic lobe is one of the five lobes of the brain and the area of cortex that appears to lie around the junction between the cerebral hemispheres and the brain stem. The limbic lobe functions in the expression of emotions and memory. |
Lincosamides
| Often used as second line therapy, Lincosamides are an antibiotic commonly used against Gram positive organisms. They act by preventing bacteria from producing proteins needed for their growth and reproduction. |
Lipase
A lipase is an enzyme that breaks triglycerides down into fats. |
Lipex
| Lipex is used to help lower cholesterol and triglyceride levels. Lipex is used in patients who have coronary heart disease or who are at high risk of coronary heart disease, (for instance, if they have diabetes, a history of stroke, or other blood vessel disease). |
Lipids
| Oily substances that include things like fats, oils and waxes. Sebum is made up of lipids. |
Lipitor
| Lipitor is a cholesterol-lowering medication. |
Lipodystrophy
Lipodystrophy is a medical condition which is characterized by abnormal degeneration of the body's adipose (fatty) tissue.
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Lipoma
| Lipomas are common benign tumours of mature fat cells situated in the subcutaneous tissue. They are usually soft and mobile, well defined lumps of rubbery consistency which may occur as one or many. Often lipomas are painless and occur most commonly of the trunk and limbs (especially arms). |
Lipoprotein
| A lipoprotein is a protein joined to a lipid. |
Liposarcoma
| Liposarcoma is one of the commonest sarcomas of adulthood, where sarcomas comprise 1% of all adulthood malignancies. It appears in the forties to sixties and are uncommon in children. They usually grow in the deep soft tissue of the limbs and trunk. They are able to grow into a very large size. Depending on the cellular make-up, they can either be dormant or aggressive. |
Liposuction
| Liposuction is the removal of superficial (close to the surface) fat deposits via suction. It is often included as a type of surgery for weight loss but is mainly indicated for cosmetic and body shaping purposes. Liposuction can only remove deposits of fat from under the skin and cannot remove fat build up in arteries or organs. Examples include liposuction of excess fat from the abdomen (tummy) or thighs. |
Litak
| Litak is used in the treatment of hairy cell leukaemia, and second line treatment of Waldenstrom's macroglobulinaemia (also called lymphoplasmacytic lymphoma, which is a type of non-Hodgkin's lymphoma) if alkylating agents fail. |
Lithotomy position
| The lithotomy position is used in childbirth and gynacological examinations. It involves the woman lying on her back with her legs apart supported by stirrups so the knees and hips are bent. |
Live attenuated intranasal vaccine (LAIV)
Live attenuated intranasal vaccine (LAIV) are a type of influenza vaccine that have been in use overseas since 2003, but have not yet been licensed in Australia. LAIV are given by squirting the vaccine into the nose (as a nasal spray), so injection is not required. In years where the surface particles in the vaccine do not match the particles on the virus very well, LAIV is more effective than the inactivated virus vaccine. LAIV is more effective in young children regardless of how well the flu season virus and vaccine particles match. The main side effect from LAIV is mild and short term sore throat and runny nose. After vaccination with LAIV, the person ‘sheds' influenza virus from their nose and throat, however it is extremely rare that another person would catch influenza from this. |
Liver Cirrhosis
Liver cirrhosis is a chronic condition characterised by declining liver function as a result of scar tissue formation in the liver. It is commonly associated with long term alcohol or drug abuse. |
Liver Transplant
| A liver transplant is a surgical treatment for severe liver disease. It involves removal of the patient's diseased liver and insertion of a donor liver. The replacement liver may be donated by a live donor (living donor transplantation), or from a person who has just died (cadaveric donation). |
Lobe
| A lobe refers to a part or portion of an organ. For example the brain has four lobes: the frontal lobe, parietal lobe, occipital lobeand temporal lobe. |
Lobectomy
| A lobectomy is literally just the removal of a 'lobe' of an organ, which can be thought of as a sub-section. A lobectomy can be the removal of one lobe of the lung, usually for the treatment of non-small cell lung cancer (NSCLC); however, it can also refer to the removal of a lobe in the liver, or even the temporal lobe in the brain. |
Lobular Carcinoma of the Breast (Breast Cancer)
| Lobular Carcinoma of the Breast is one of the main types of breast cancer. Lobular carcinoma is the second most common type of breast cancer, making up about 10% of all breast cancers. |
Local anaesthetic
| Local anaesthetic is a drug that reversibly blocks the transmission of signals along the nervous pathway. It is used either for pain relief or paralysing (loss of muscle power). |
Locilan 28 Day
Locilan 28 Day is a birth control pill commonly known as a "progestogen-only" pill or "mini pill". Locilan 28 Day is usually given to women who are unable to take other types of birth control pills or use intrauterine devices (IUDs). |
Loette
| Loette is an oral contraceptive, used to prevent an unintended pregnancy. Loette can also help clear up moderate acne and help with periods which are very heavy, painful or irregular. |
Low back pain
| Low back pain means a back pain roughly between the bottom of the ribs and the top of the legs at the back. Importantly, the pain often radiates to the buttocks, and sometimes further down the leg and even to the foot. |
Low birth weight infant
| A low birth weight infant refers to an infant born weighing less than 2.5kg. |
Low calorie diet (LCD)
| Low calorie diets are a treatment option for obesity aimed at producing weight loss. The programs work by replacing meals per day with specialised formula food, which is a complete meal. As the body no longer receives as many calories, it turns to breakdown of fat stores for energy. However, these programs may not be for everyone, as it requires a strict regimen and lifestyle modifications. |
Low vision
 3D Animation on Low Vision This animation brought to you by Blausen Medical Communications. Contact Andrew Walbank. |
Low-dose single-agent chemotherapy
| Low-dose single-agent chemotherapy is a medication regime to treat cancer which has a highly toxic effect. Single agent chemotherapy refers to a treatment regime which involves only one type of medication, given in low doses to reduce the toxic effects on the body. It is appropriate for benign and locally metastasising tumours, or those which are highly responsive to chemotherapy (e.g. gestational trophoblastic tumours). |
Lubricant (sexual)
| Lubricant is a gel or cream used during sexual intercourse by a woman to prevent pain and trauma on insertion of a man's penis. |
Lucentis
| Lucentis is a medication used to treat neovascular age-related macular degeneration (AMD). |
Lumbar Fusion
| Lumbar Fusion is when two or more vertebra are joined with bone fragments, when this sets is fuses. |
Lumbar laminectomy
| Lumbar laminectomy is a surgical procedure most often performed to treat leg pain related to herniated discs, spinal stenosis, and other related conditions. Stenosis occurs as people age and the ligaments of the spine thicken and harden, discs bulge, bones and joints enlarge, and bone spurs or osteophytes form. Spondylolisthesis (the slipping of one vertebra onto another) also can lead to compression. |
Lumbar Puncture (Spinal Tap)
| A lumbar puncture (LP), often called a spinal tap, is a procedure in which a small amount of the fluid that surrounds the brain and spinal cord, called the cerebrospinal fluid (CSF), is removed and examined. |
Lumbo-sacral
The lumbo-sacral area of the spine is composed of the lumbar vertebrae and the sacrum. For more information see Anatomy of the Spinal Cord |
Lumbricals
| Lumbricals are four worm-like muscles of the hand that flex the fingers at metacarpophalangeal joints and extend them at interphalangeal joints. |
Lumin
| Lumin is a medication used in the treatment of clinical depression. |
Lunate
The lunate is one of eight carpal bones that make up the wrist of the hand. The other bones are the scaphoid, triquetral, pisiform, trapezium, trapezoid, capitates and hamate.
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Lung function tests
| Lung function tests are simple investigations that provide information about how the lungs are working. The most important of these tests include spirometry, measurement of lung volumes and measurement of how well the air spaces in the lungs transfer oxygen to the blood (called diffusion capacity). |
Lung Transplant
Lung transplantation is a surgical treatment similar to heart transplantation where your lung or lungs are replaced by that of a donor. Lung transplantation is now an accepted treatment method for patients with severe lung diseases who meet defined selection criteria. Chronic obstructive pulmonary disease (COPD) is the most common indication for lung transplantation. |
Lung volume
| Lung volume refers to the total amount of air that is contained in the lungs. Total lung volume (or capacity) includes the amount of air you breath in as well as the small amount of air that is always stuck in your lungs (residual volume). Lung volumes are often measured as part of lung function tests. To determine your lung volume, gas dilution tests are used where you breathe a certain gas from a container and the change in concentration is measured. From the fall in concentration of gas, the physician can deduce how much space is in your lungs. |
Lungs
| Lungs are paired, cone-shaped organs which take up most of the space in our chests, along with the heart. Lungs are part of the respiratory system and are important in ensuring the entry of oxygen into the body and the removal of carbon dioxide out of the body. |
Lunula
| Lunula refers to the white "moon" on the nail distal that is more commonly visible on the thumb and great toe. It may sometimes be concealed by the nail fold. |
Lupus
| Lupus is a chronic skin condition which may appear as round, plaque-like areas of the skin, brownish nodules on the skin or scarring. |
Lupus anticoagulant
| This is a special type of antibody that interferes with the normal function of blood vessels. This antibody causes narrowing of the blood vessels and increased likelihood of blood Clotting. They react with proteins in the blood that are bound to fat molecules. The presence of these antibodies can lead to complications such as strokes and recurrent miscarriages. |
Luteal phase
| Luteal phase is generally days 14 - 28 of a women's menstrual cycle (28 day cycle). This phase is initiated with the mid-cycle surge of LH which coincides with ovulation and ends with the first day of onset of the period. |
Luteal phase of the menstrual cycle
| The luteal phase of the menstrual cycle is the post-ovulation phase of the menstrual cycle. |
Luteinising hormone (LH)
Luteinising hormone (LH) is a hormone that is produced by the anterior pituitary gland. In females LH triggers ovulation and in males it stimulates the production of testosterone to aid sperm maturation. |
Lyme disease
| Lyme disease is caused by a bacterial infection transmitted by ticks, and the individual's subsequent immune reaction to the infection. It is characterised by arthritis, neurological and cardiac complications, with a characteristic rash that spreads from the initial tick bite. |
Lymph
| Lymph is the fluid present within the lymphatic system. It is mostly composed of excess fluid taken away from tissues and is similar in composition to blood but with no red blood cells, and many lymphocytes. It re-enters the blood via the veins. |
Lymph Node
| Lymph nodes are part of the lymphatic system and play a role in immunity. Groups of lymph nodes are found in areas such as the groin and armpit. They contain lots of lymphocytes and act as a filter for the lymph, removing 99% of foreign particles. |
Lymph node dissection
| Lymph node dissection is the surgical removal of a regional lymph node area. This is needed when the distance between the primary tumour and the regional lymph node area is too wide, making it necessary to resect the two areas separately. |
Lymphatic System
| The Lymphatic System is a network of very small vessels that carry lymph througout the body. Along the lymphatic syststem there are numerous lymph nodes. |
Lymphobiopsy
| Lymphobiopsy is the sampling or removal of lymph nodes during surgery. |
Lymphoblasts
| Lymphoblasts are normal precursor cells in the Bone marrow that differentiate to become mature lymphocytes. |
Lymphocytes
| A lymphocyte is a white blood cell and part of the Immune System. They are found in the lymph nodes, spleen, and many other parts of the body. They can be sub-divided into B Cells and T Cells. |
Lymphoscintigraphy
| Lymphoscintigraphy is a type of nuclear medicine study. It may be used before cancer surgery to determine whether the cancer has spread. |
Lyrica
| Lyrica is an anticonvulsant drug used for the treatment of epilepsy. It consists of an active ingredient known as pregabalin, which works by slowing down the impulses in the brain that causes seizures or fits. Lyrica also has analgesic effects, which makes it a useful candidate for treating neuropathic pain. |
Lysozyme
| Lysozyme is a type of enzyme that speeds up a chemical reaction that destroys certain bacteria. Its action is part of the Innate Immune System. |
