Complications

There are several problems that often occur with mumps. These can be worrying, but they're rarely serious and usually improve as the infection passes.

Common complications

Swollen testicle

Pain and swelling of the testicle (orchitis) affects up to 1 in 3 males who get mumps after puberty. The swelling is usually sudden and affects only one testicle. The testicle may also feel warm and tender.

In affected boys and men, swelling of the testicle normally begins 4 to 8 days after the swelling of the parotid gland. Occasionally, swelling can occur up to 6 weeks after the swelling of the glands.

Any testicle pain can be eased using painkillers such as paracetamol or ibuprofen you buy from the pharmacy or supermarket. If the pain is particularly severe, contact your GP, who may prescribe you a stronger painkiller.

Applying cold or warm compresses to your testicle and wearing supportive underwear may also reduce any pain.

Just under half of all males who get mumps-related orchitis notice some shrinkage of their testicles and an estimated 1 in 10 men experience a drop in their sperm count (the amount of healthy sperm their body can produce). However, this is very rarely large enough to cause infertility.

Swollen ovaries

About 1 in 15 females who get mumps after puberty experience swelling of the ovaries (oophoritis), which can cause:

• lower abdominal pain
• high temperature
• being sick

The symptoms of oophoritis usually pass once the body has fought off the underlying mumps infection.

Viral meningitis

Viral meningitis can occur if the mumps virus spreads into the outer protective layer of the brain (the meninges). It occurs in up to 1 in 4 cases of mumps.

Unlike bacterial meningitis, which is regarded as a potentially life-threatening medical emergency, viral meningitis causes milder, flu-like symptoms, and the risk of serious complications is low.

Sensitivity to light, neck stiffness and headaches are common symptoms of viral meningitis. These usually pass within 14 days.

Pancreatitis

About 1 in 25 cases of mumps lead to short-term inflammation of the pancreas (acute pancreatitis). The most common symptom is sudden pain in the centre of your belly.

Other symptoms of acute pancreatitis can include:

• feeling or being sick
• diarrhoea
• loss of appetite
• high temperature
• tenderness of the belly
• less commonly, yellowing of the whites of the eyes and the skin (jaundice), although this may be less noticeable on black or brown skin

Although pancreatitis associated with mumps is usually mild, you may be admitted to hospital so your body functions can be supported until your pancreas recovers.

Rare complications of mumps

Rare but potentially serious complications of mumps include an infection of the brain itself, known as encephalitis. This is thought to occur in around 1 in 1,000 cases of mumps. Encephalitis is a potentially fatal condition that requires admission to a hospital intensive care unit.

About 1 in 25 people with mumps experience some temporary hearing loss, but permanent loss of hearing is rare. It's estimated this occurs in around 1 in 20,000 cases of mumps.

Mumps and pregnancy

In the past it was thought developing mumps during pregnancy increased the risk of miscarriage, but there's little evidence to support this.

But, as a general precaution it's recommended pregnant women avoid close contact with people known to have an active mumps infection (or any other type of infection).

If you're pregnant and you think you've come into contact with someone with mumps but you haven't been vaccinated, contact your GP or midwife for advice.