Virtual Medical Centre

N-3 fatty acids are essential fatty acids which the body cannot produce through chemical reactions. Instead, N-3 fatty acids must be consumed from plant or animal sources. Fish is the best available source of N-3 fatty acids.

A narcotic is a potent prescription only pain relief medication. Narcotics diminish the sensitivity to pain.

• Allergic rhinitis
• Nasal Polyps

Nasopharyngitis is the medical term used to refer to the common cold.

For more information, see Common Cold.

Nebcin is used to treat serious infections caused by bacteria. Nebcin is used to treat infection of the blood, meningitis, urinary tract infection, pneumonia, bronchitis, burns, and infection of gastrointestinal tract.¹

Semen in which all sperm are non-viable or non-motile.

More on sperm analysis.

Negative reinforcement is a technique used to try and change maladaptive behaviours by taking away a negative feeling or experience in order to achieve a desired behaviour. For example, telling a child they do not have to do the dishes if they behave, as opposed to telling them they will have to do the dishes if they misbehave. This technique is used in behaviour therapy.

Nephritis is a condition characterised by inflammation of the kidneys.

Nephrotic syndrome occurs when the small blood vessels that feed the kidneys become damaged. Symptoms include hypertension, high urinary protein and low blood protein.

For more information, see Nephrotic Syndrome.

Nerve sparing surgery is a type of surgery that tries to save the nerves near the tissue being removed (e.g. during radical prostatectomy). Bilateral nerve sparing surgery tries to save the nerves on both sides of the prostate.

Neural tube defects are defects, present from birth, involving the spinal cord and brain.

A neurostimulator is a battery powered implantable device designed to deliver electrical stimulation to treat neurological disorders.

Neutropenia is a condition in which an individual has a low blood neutrophil count.

For more information, see Neutropenia.

Newborn screening tests a baby for a number of diseases including cystic fibrosis (CF). This is usually done via a small blood sample taken from the baby a few days after birth.

Nicabate CQ and Nicabate CQ Clear are patches used to stop smoking. They help you give up smoking by replacing some of the nicotine you are used to getting from cigarettes. The treatment is called Nicotine Replacement Therapy (NRT). NICABATE CQ and Nicabate CQ Clear Patches releases nicotine over a period of time at a constant rate. This will help easing unpleasant symptoms such as feeling ill or irritable that smokers often feel when they try to give up. The nicotine can also reduce your cravings for a cigarette and help you to resist the urge to smoke.

Nicabate CQ Lozenges are used to stop smoking. They help you give up smoking by replacing some of the nicotine you are used to getting from cigarettes. The treatment is called Nicotine Replacement Therapy (NRT). Nicabate CQ Lozenges will help easing unpleasant symptoms such as feeling ill or irritable that smokers often feel when they try to give up. The nicotine can also reduce your cravings for a cigarette and help you to resist the urge to smoke.

Nizoral is a medication used to treat systemic and deep fungal infections that does not respond to other treatment. Conditions treated include resistant pityriasis versicolor, prevention of mucocutaneous candidiasis in mmunocompromised, mucocutaneous candidiasis and vaginal thrush where topical treatment has failed.

Nocioceptive pain is what is considered to be "normal" pain resulting from activation of pain pathways after the inflammation, damage or shock of nerve endings. This is in contrast to neuropathic pain, in which the nerve endings fire abnormally.

Nocturnal penile tumescence (NPT) testing for erectile dysfunction involves wearing a monitor on the penis overnight. The data from this monitor is then assessed to analyse how often erections occurred, how long they lasted, and how rigid and large the penis was during the erections. May be carried out at home or in sleep laboratories.  

A nodule is a small round clumping of cells of varying size and consistency. If located close to the skin surface, often they can be felt with the fingertips as spherical shapes and may be visible as elevations protruding above the skin.

Non-arteritic anterior ischaemic optic neuropathy (NAION) is a medical condition where damage to the optic nerve occurs due to inadequate blood supply. It is characterised by sudden and painless loss of vision in the eye, accompanied by pallied swelling of the optic disc.

Non-disjunction is a error during meiosis. During meiosis the chromosome pairs seperate and migrate to opposite sides of the cell ready for cell division, this process is called disjunction. Disjunction assures each daughter cell receives its own copy of that chromosome. Non-disjunction occurs when the chromosomes fail to seperate resulting in one daughter cell with one too many of the chromosome and one daughter cell with one too little.

Non-prescription or over-the-counter (OTC) drugs are medications that do not need clearance from a doctor in order to purchase and use. Depending on the particular medication, some OTC medicines can be found in supermarkets, convenience stores and petrol stations or can be purchased online.

Non-ST segment elevation myocardial infarction (NSTEMI) is a type of coronary artery disease that is associated with sudden rupture of plaque inside the coronary artery. This type of myocardial infarction (MI) does not cause changes on an electrocardiogram (ECG). However, chemical markers in the blood indicate that damage has occurred to the heart muscle. In NSTEMI, the blockage may be partial or temporary, and so the extent of the damage relatively minimal.

That is, normal sperm, is the classification for semen which falls within all the WHO reference values.

More on male reproductive system.

More on sperm analysis.

Notifiable infections or diseases are conditions which health professionals must report to a central agency every time they are diagnosed (e.g. chlamydia).

Nucleotides are the base units that make up DNA and RNA. The nucleotides that make up DNA include; Adenine (A), Thymine (T), Cytosine (C) and Guanine (G). The nucleotides are paired up in DNA in a complimentary fashion; A and T are always bound together and G and C are always bound together. This complimentary pairing is very important for DNA replication and protein synthesis and is the reason that nucleotides are commonly referred to as base pairs. The nucleotides that make RNA include; Adenine (A), Uracil (U), Cytosine (C) and Guanine (G).