Common complications
Common complications of mumps include:
- pain and swelling of the testicles (orchitis) – which affects 20% of all males who get mumps after puberty
- pain and swelling of the ovaries (oophoritis) – which affects 5% of all females who get mumps after puberty
- inflammation of the pancreas (pancreatitis) – which occurs in 5% of cases
- viral meningitis – which occurs in an estimated 1-10% of all cases.
Orchitis, oophoritis, viral meningitis and pancreatitis are explained in more detail below.
Orchitis
The most common symptom of orchitis is the painful swelling of the testicles. The pain can range from mild to severe. The testicles usually begin to swell 4-8 days after the onset of mumps symptoms.
Other symptoms of orchitis include:
- high temperature (fever) of 38ºC (100ºF) or above
- vomiting
- headache
- a general feeling of being unwell
The swelling should resolve within a week, although your testicles may feel tender for several weeks.
Symptoms of pain can be eased using over-the-counter (OTC) painkillers, such as paracetamol or ibuprofen. If the pain is particularly severe, contact your GP who may prescribe a stronger painkiller for you.
Applying cold compresses to your testicles, and wearing supportive athletic underwear, may also reduce any pain.
An estimated 50% of men who get mumps will notice some shrinkage of their testicles. An estimated 7-13% of men will experience a drop in their sperm count (the amount of healthy sperm that their body can produce). However, this is rarely large enough to cause infertility.
Oophoritis
Oophoritis is the inflammation (swelling) of your ovaries, which can cause symptoms of:
- lower-abdominal pain
- high temperature (fever) of 38ºC (100ºF) or above
- vomiting
The symptoms of oophoritis usually pass once the body has fought off the underlying mumps infection.
There have been a number of cases where oophoritis has triggered an early menopause and caused infertility. But this is thought to be rare.
Pancreatitis
The most common symptom of pancreatitis is the sudden onset of pain in the centre of your upper abdomen. Other symptoms of acute pancreatitis can include:
- nausea
- vomiting
- diarrhoea
- loss of appetite
- high temperature (fever) of 38ºC (100ºF) or above
- tenderness of the abdomen and, less commonly, yellowing of the skin and the whites of the eyes (jaundice)
Although the pancreatitis associated with mumps is usually mild, admission to hospital may be recommended so that your body functions can be supported until your pancreas recovers.
Viral meningitis
Viral meningitis is a viral infection of the outer membranes (meninges) of your brain and spinal cord.
Unlike bacterial meningitis, which is regarded as a potentially life-threatening medical emergency, viral meningitis causes much milder, flu-like symptoms, and the risk of serious complications are low.
Symptoms of viral meningitis include:
- high temperature (fever) of 38ºC (100ºF) or above
- sensitivity to light (photophobia)
- headache
- nausea
- vomiting
The symptoms of viral meningitis usually pass within 14 days.
Mumps and pregnancy
Women who develop a mumps infection during the first 12-16 week of pregnancy have a slightly higher risk of miscarriage. There is no evidence that mumps causes birth defects.
Rare complications of mumps
Rare but potentially serious complications of mumps include:
- a serious brain infection (encephalitis), which occurs once in every 6,000 cases
- permanent hearing loss, which occurs once in every 15,000 cases.
Encephalitis requires emergency admission to an intensive care unit (ICU). Unfortunately, there is currently no treatment to reverse hearing loss.
