Ovaries are the female gonads. They produce eggs and secrete sex hormones, oestrogens and progesterone. They are suspended on each side of the uterus by a tough structure known as the ovarian ligament. They are also loosely clasped by frond-like structures called fimbriae, which guide an egg into the fallopian tube, and thence to the uterus, where fertilisation may take place.

A woman's full quota of eggs is established before she is even born. At puberty, the hormones secreted by the ovary enable sexual maturation and allow the womb to accommodate and sustain the process of pregnancy.

Disorders of the ovary range from mild to severe. Mittelschmerz is a cramp that some women experience around the middle of their menstrual cycle as ovulation occurs. Ovarian cysts are fluid-filled sacs which usually affect women during their reproductive years. Most don't need treatment, although some require surgery. Polycystic ovary syndrome is a condition in which multiple cysts form, often causing hairiness, acne and fertility difficulties.

Ovarian cancer is sometimes known as "the silent killer". Because ovarian enlargement often produces no symptoms, these tumours are commonly advanced before diagnosis. Even when patients do feel discomfort, it tends to occur as a general sense of bloating or tummy-ache, which is easily confused with more benign illnesses. Surgery, chemo and radiotherapy form the mainstay of treatment, but the best hope for the future reduction of deaths from this disease lies in finding a way to pick it up much sooner.

• Gabriel Weston is a surgeon and author of Direct Red: A Surgeon's Story.