Conditions

A black eye is blood that has leaked from small vessels into the skin of the eyelids and around the eye socket after a blow, a fall or facial surgery.

Bladder cancer starts in the lining — the layer that covers the bladder from the inside and sits in urine all the time.

This is long-standing pelvic pain arising from the bladder, together with frequent and urgent needs to pass urine, in the absence of any infection in the urine.

A bladder stone is a hard lump made of urinary salts that has grown inside the bladder itself, rather than travelling down from the kidney.

Blepharitis is inflammation of the eyelid margin — the narrow strip where the lashes grow and the ducts of the oil glands open.

A blister is the skin's answer to repeated friction: the layers separate and the gap fills with fluid, which cushions and protects the tissue underneath.

A boil is a deep bacterial infection of a hair follicle and the tissue around it. A painful lump forms and gradually fills with pus.

Bone cancer usually means a malignant tumour that starts in the bone itself. Doctors use a more exact word — bone sarcoma — because it grows not from lining…

A bone cyst is a cavity inside a bone filled with fluid or with blood. It is not cancer: it does not seed into other organs.

Botulism is a rare poisoning caused by a toxin made by the bacterium Clostridium botulinum.