An attack of shingles can increase the risk of having a stroke or heart attack years later, new research suggests.
For people under the age of 40, the viral infection boosted the chances of a stroke by 74% and a heart attack by 50%.
Older individuals were less affected, but shingles increased their risk of a heart attack by 10% and of a "mini-stroke" or transient ischaemic attack (TIA) by 15%.
Researchers studied data on 106,000 patients with shingles and 213,200 matched non-sufferers. Patient records were reviewed for an average of six years after a shingles diagnosis and in some cases for as long as 24 years.
A total of 40 people with shingles went on to experience a stroke, compared with 45 of those who did not have shingles.
People under 40 affected by shingles were more than twice as likely to have a TIA.
Shingles is caused by the same virus responsible for chicken pox, which can lie dormant in nerve roots for years before awakening and producing a painful rash.
Stress and inflammation may explain the link between shingles and stroke, scientists believe.
Heart Attack Signs You Might Be Ignoring...
Heart Attack Symptoms You're Likely To Ignore(01 of07)
Open Image Modal (credit:Alamy)
Burning Pain In Abdomen(02 of07)
Open Image Modal"A dull ache or burning sensation in the epigastrum (upper part of the abdomen). Not all pain typically occurs in the centre of the chest," explains Dr Sanjay Sharma. "The blockage in the heart could cause symptoms similar to indigestion (like fullness, bloating and problems swallowing). If these symptoms longer than two days, seek medical advice." (credit:Alamy)
Aching Neck And Jaw (03 of07)
Open Image Modal"Severe pain or pressure sensation around the jaw and neck only could be a sign," says Dr Sanjay Sharma. "If it starts off as a mild discomfort but gradually worsens, seek medical advice immediately." (credit:Alamy)
Upper Back Pain(04 of07)
Open Image Modal"Pain in the centre of the upper back is often mistaken for muscular pain, but could be a 'silent heart attack' symptom," says Dr. Sanjay Sharma."If in doubt, speak to a medical professional as soon as possible." (credit:Alamy)
Breathlessness(05 of07)
Open Image Modal"Being suddenly short of breath, without any chest pain could be a sign of a herat attack - although it's more likely to occur in elderly people or diabetics. The chest pain could be due to the lack of oxygen to the heart muscle," says Dr Sanjay Sharma. "The breathlessness is often due to the fact that the heart is no longer pumping properly causing the lungs to fill up with fluid." (credit:Alamy)
Dizziness And Sweating(06 of07)
Open Image ModalDizziness and sweating is a common sign," says Dr Sanjay Sharma. "The sweating is a normal reaction to severe pain and the loss of consciousness may be due to a drop in blood pressure the heart going into a very slow, or very fast electrical rhythm, due to the effects of lack of oxygen." (credit:Alamy)
'Pulled Muscle'(07 of07)
Open Image Modal"If chest pain spreads to your left or right arm, that could be another sign you're having a heart attack. We've heard from heart attack survivors who thought they'd pulled a muscle and waited until the following day before getting themselves to hospital," adds Ellen Mason, senior cardiac nurse from the British Heart Foundation. (credit:Alamy)
Study author Dr Judith Breuer, from University College London, said: "Anyone with shingles, and especially younger people, should be screened for stroke risk factors.
"The shingles vaccine has been shown to reduce the number of cases of shingles by about 50%. Studies are needed to determine whether vaccination can also reduce the incidence of stroke and heart attack.
"However, what is also clear is that factors that increase the risk of stroke also increase the risk of shingles, so we do not know if vaccinating people can reduce the risk of stroke per se. Current recommendations are that anyone 60 years and older should be vaccinated. The role for vaccination in younger individuals with vascular risk factors needs to be determined."
The findings are published in the online issue of the journal Neurology.