Medical dictionary

What is asthma? Asthma is a condition which occurs when the upper airways constrict as a result of a particular trigger, for example, an extreme reaction to some sort of allergen/stimulus such as viral infections, pollen, or overwhelming stress or exercise. Asthma can present at any age though it is usually not diagnosed in early childhood (especially infants) unless there is a strong fa

What is asthma in children? Asthma is a common pulmonary condition that often begins during childhood. The lungs and airways become inflamed and produce mucus when exposed to certain triggers. Common triggers include allergies, colds and exercise.   What are the symptoms? Difficulties breathing or shortness of breath Tightness in the chest Congestion Intermi

What is astigmatism? Astigmatism is a condition where the shape of your eye is more like a rugby ball than a football, causing blurriness in vision. People with astigmatism are generally born with it, but sometimes the condition can develop as a result of surgery, injury, or an illness. Astigmatism is usually accompanied with long-sightedness or short-sightedness. What are the

What is ataxia? Ataxia is the term for a group of neurological disorders that affect muscle control, causing difficulties with balance, coordination and speech. There are different types of the disorders that can affect people in different ways. Any part of the body can be affected by ataxia but overall people have difficulties with: Balance and walking: People with ataxia have

What is atherosclerosis? Atherosclerosis is the most frequent disease of the arteries. It consists of the formation of plaque in the blood vessels through which oxygen and nutrients are transported. The plaque is a sticky substance formed by fat, cholesterol or calcium, which over time can harden and narrow the arteries causing a lack of blood flow to the tissues and organs. Although it often a

What is atheroembolic renal disease? Atheroembolic renal disease occurs when minute particles become dispersed along the small blood vessels in the kidneys. These particles are made of solidified fat and cholesterol, and other substances. What are the symptoms of atheroembolic renal disease? It should be borne in mind that the disease may be asymptomatic. If there are symptoms, t

What is atopic dermatitis?   Atopic dermatitis (or atopic eczema) is a chronic inflammation of the skin that results in an itchy rash. It is more common in children than adults.   This condition is “atopic” because it does not affect a specific area; it can affect several different areas of the body and is not necessarily where the skin is in direct contact with a

What is Atrial Fibrillation (AF)?   Atrial fibrillation is the most common heart rhythm disorder in the world. It is characterised by a rhythm disturbance that causes the heart to beat fast or irregularly. It affects around 4% of people over the age of 65. The atria, the upper chambers of the heart that control the rhythm, don’t function as they should and cause the hear

What is atrial fibrillation ablation? Atrial fibrillation ablation is a procedure used to treat atrial fibrillation - a type of abnormal heart rhythm also known arrhythmia. It works by scarring the inside of the heart, by burning or freezing parts of the heart tissue, to help alter or break up electrical signals that cause irregular heartbeats. There are a group of cells in the heart that st