The appendix is a small pouch joined to the large intestine at a point called the caecum. Appendicitis is inflammation and infection of the appendix. This information from Great Ormond Street Hospital (GOSH) explains the causes, symptoms and treatment of appendicitis and where to get help.
Arrhythmias are abnormal heart rhythms, which can prevent the heart pumping efficiently. This page from Great Ormond Street Hospital (GOSH) explains how the heart beats normally, what happens when it starts to beat abnormally and how it can be treated.
Arthritis is a painful condition that affects the joints and bones, and can make it difficult for you to move around. You might think it just affects older people, but young people can experience it too. The tissue lining the joints, like elbows and knuckles, becomes inflamed, making them stiff and swollen.
Asthma is a condition that affects the small airways of the lungs (bronchi), making them red, swollen and sensitive. These sensitive or hyper-responsive airways can react badly to certain ‘triggers’ such as catching a cold, exercise, cigarette smoke, house dust mites, pets and pollen.
An atrioventricular septal defect results in a is a large hole between the upper filling chambers (atria) and the lower pumping chambers (ventricles) of the heart. There is also only one valve between the atria and ventricles instead of two.