Read about abdominal aortic aneurysm (AAA), which is a bulge or swelling in the aorta (the main blood vessel running from the heart to the tummy).

Find out who is offered abdominal aortic aneurysm (AAA) screening, why it’s done and what it involves.

Find out what an abortion involves, how you can get one on the NHS, and what support is available to help you make a decision.

Read about skin abscesses and internal abscesses. An abscess is a painful collection of pus, usually caused by a bacterial infection.

Acanthosis nigricans is the term for darkened, thickened patches of skin in the armpit and around the groin and neck. Find out about the main causes and treatments.

Read about achalasia, a disorder of the gullet (oesophagus) where it loses the ability to move food along. The valve at the end of the gullet also fails to open.

This guide includes everything you need to know about caring for a baby.

Find out how to relieve back pain, what can cause it, and when to get medical advice.