Nystagmus is the involuntary movement of the eyes, causing them to flick rapidly from side to side, up and down, or in a rotary manner. It can be a visual symptom of multiple sclerosis.

Double vision (diplopia) can occur in multiple sclerosis when the nerve pathways that control eye movements are damaged.

Optic neuritis is a common eye problem where inflammation or demyelination affects the optic nerve. It is a condition in its own right, but is also strongly associated with multiple sclerosis. Not everyone who experiences optic neuritis goes on to develop further symptoms of MS, but a significant proportion do.

Urinary tract infections (UTIs) are a common bladder problem in multiple sclerosis. They are also known as water infections or cystitis. UTIs can cause you to feel a frequent urge to urinate and make urinating painful. Treatment is with a course of appropriate antibiotics.

Stumbling or tripping may have been one of the first symptoms you noticed. Walking problems are common in MS, and have a variety of causes.

Spasticity and spasms are common symptoms of multiple sclerosis that may cause your muscles to feel stiff and heavy, or cause them to move unpredictably.

A sudden, electric shock-like feeling that passes down the back of the neck and can reach the fingers and toes. Find out more about Lhermitte's sign, why it happens and how to manage it.

Living with MS can have a profound impact on sex drive and sexual desire. Factors including your MS symptoms, confidence and stress can reduce desire for sex.

Sexual difficulties, including difficulty reaching orgasm, are common in men with MS. Sexual issues often result from a complex interaction of physical, social, psychological and emotional elements. Read more in this A-Z entry.

Erectile dysfunction (ED), sometimes called impotence, is a common symptom for men with multiple sclerosis (MS).