What Is Shingles? Symptoms, Causes, Diagnosis, Treatment, and Prevention

Shingles, also known as zoster or herpes zoster, is a viral infection caused by the varicella zoster virus (VZV), the same virus that causes chickenpox.

Anyone who's had chickenpox can get shingles. After you've been infected with chickenpox, the varicella zoster virus lies inactive in your body — mostly in spinal or cranial nerves — usually for many decades. If the virus reactivates, it can travel along nerve pathways to your skin and cause a painful rash to erupt.

If you’re over 50 or over 18 and immunocompromised, you can get a shingles vaccine to prevent it.

Shingles usually appears as a single stripe of blisters around the left or right side of the body. Less commonly, it can occur on one side of the face. It is almost always unilateral, meaning it involves only one side of the body.

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Is That Rash by My Eye Really Shingles?

Shingles tends to show up most frequently on the torso, just because of the laws of probability, notes Joseph Safdieh, MD, a professor of neurology at Weill Cornell Medicine in New York City. In that area of your body, there are 24 nerves that can host the virus, compared with the 10 in your lower back.

Often, it’s not what the rash looks like, but what it feels like before and after it shows up, that signals the condition. Up to several days before the shingles rash appears, pain, itching, or tingling often occurs in the area where it will develop.

In the days before the rash appears, a variety of other flu-like symptoms of shingles can occur. You may experience:

• Chills
• Fever
• Headache
• Upset stomach

You may even experience the pain but not the rash. Because the pain of shingles originates in the nerves, it may have a different quality than any other pain you may have experienced before.

“Neuropathic pain is burning,” says Dr. Safdieh. “It’s both numb and painful at the same time, and can be provoked by touching the skin.” Your skin may be so sensitive that even sunlight can bring on a stabbing sensation.

Even if you aren’t sure you have shingles, you should still see a doctor right away, because immediate treatment can prevent complications like long-term nerve pain.

Learn More About the Signs and Symptoms of Shingles

The varicella zoster virus — the virus that causes chickenpox and shingles — is part of a group of viruses called herpes viruses. This group also includes the viruses that cause cold sores (oral herpes) and genital herpes.

But the varicella zoster virus is not the same virus that causes cold sores and genital herpes. The viruses that cause oral and genital herpes are herpes simplex 1 and herpes simplex 2.

If you’ve had chickenpox, you can get shingles. After the chickenpox is over, varicella zoster lies inactive, mainly in spinal or cranial nerves. Sometimes the virus reactivates, and that’s when it travels along the nerves to erupt as a rash on your skin, causing shingles.

Risk Factors

The risk of shingles increases as you age, which may be due to lowered immunity to infections as you grow older.

• Certain cancers, such as leukemia and lymphoma
• HIV or AIDS
• Immunosuppressive medications, such as corticosteroids, which are used in the treatment of cancer and autoimmune conditions like rheumatoid arthritis, as well as drugs that are given to people who have undergone an organ transplant

Is Stress a Risk Factor for Shingles?

You may have heard that someone got shingles because they were stressed, perhaps after the death of a relative, soon after a divorce, or at the end of a difficult semester at school.

“There’s some controversy about the matter,” says Safdieh. “We know for a fact that stress can have an impact on the function of the immune system. If there’s stress, immunity is depressed, and I certainly see patients who tell me they were having a lot of stress when they got shingles.” But, he adds, “there are many people who are stressed and don’t get shingles, and many people who get them while they’re on vacation.”

If there is a link between stress and shingles, it’s probably not that the stress itself is putting a strain on the immune system — it may be that stress creates conditions that lower immunity. “Keep in mind,” says Safdieh, “that when you’re stressed, you don’t sleep and you don’t eat, and all these factors can play a role.”

RELATED: How Stress Affects Your Body, From Your Brain to Your Digestive System

Prognosis of Shingles

It's uncommon to have shingles more than once, however, it's possible to get it two or more times.

Why do people get shingles more than once? “Usually it's because immunity to zoster — and other infections — normally wanes over time,” explains Dr. Oaklander. “When you have chickenpox or shingles, it boosts your immunity for the next decade or so, but if you were immunosuppressed when you contracted the chickenpox or shingles, you might not mount a robust immunity and you could get it again.”

She adds that those who are immunosuppressed because of medication or illness, such as cancer or HIV, sometimes develop prolonged, repeated, or chronic zoster infections. “That's why it's critical for people to get immunized before they get old, sick, or start immunosuppressive medication,” she says.

There’s no cure for shingles, but if you get immediate treatment, it can help speed the healing process and reduce your risk of complications.

Medication Options

Prescription or over-the-counter (OTC) pain medication may also bring relief. And if you’re 50 or older or over 18 and immunocompromised, you can receive a shingles vaccine once the disease has run its course.

Alternative and Complementary Therapies

Home remedies such as oatmeal baths can temporarily alleviate itching. Wet compresses and calamine lotion may also help soothe skin symptoms.

Learn More About Treating Shingles

Prevention of Shingles

The U.S. Food and Drug Administration (FDA) approved recombinant zoster vaccine, known as Shingrix, for adults ages 50 years old and older in 2017. In July 2021, the FDA also approved Shingrix for adults ages 18 years old and older who are or will be at increased risk of herpes zoster due to immunodeficiency or immunosuppression caused by disease or therapy, according to a press release issued by Shingrix manufacturer GlaxoSmithKline (GSK). In October 2021, the CDC's Advisory Committee on Immunization Practices (ACIP) also voted to recommend Shingrix in adults 19 years of age and older who are or will be immunodeficient or immunosuppressed due to disease or therapy, according to a press release issued by GSK.

RELATED: CDC Committee Gives Green Light to Shingles Vaccine for Immunocompromised Adults

The varicella zoster virus can spread from person to person through direct contact with the open sores of the shingles rash when blisters are present. It can also be spread by airborne droplets in people with a primary VZV infection.

Once infected for the first time, the person will develop chickenpox, not shingles.

If the rash is covered, the risk of a person with shingles spreading the virus to others is low.

But chickenpox can be dangerous for some groups of people, including premature or low birth weight infants, pregnant women who have never had chickenpox or the chickenpox vaccine, and anyone who has a weakened immune system.

So until your shingles blisters turn into scabs, you'll be able to pass the virus on to others and you should therefore avoid contact with those who could be harmed by catching chickenpox.

The following steps can help keep you from spreading the virus:

• Keep the rash covered.
• Avoid touching or scratching the rash.
• Wash your hands often.

The chickenpox vaccine was introduced in 1995 and has reduced incidence of the virus by up to 85 percent. Theoretically, this should reduce the incidence of shingles as people who were vaccinated as children grow up, but it's too soon to know if this is the case.

Essential Organizations for Shingles Information

National Institute of Neurological Disorders and Stroke (NINDS)

Along with clear, comprehensive info about shingles — what it is and how it's treated — the NINDS provides updates on research looking into why the virus reactivates and efforts to better understand what leads to ongoing pain. The NINDS site also includes links to current clinical trials.

NIH National Library of Medicine Genetics Home Reference

Here you'll find a focus on the role of genetics in shingles. Research has suggested that certain genes may be associated with whether people develop shingles or post-herpetic neuropathy.

Neuropathy Commons

Shingles — including post-herpetic neuralgia and post-herpetic itch — is among the conditions that the Nerve Unit at Massachusetts General Hospital treats and studies. Their website, Neuropathy Commons, is dedicated to helping patients find neuropathy experts and resources in their area. In addition to a searchable database of neurologists who specialize in neuropathy, the site has links to patient stories and support groups.

Favorite Podcast for Shingles Info 

Shingles: What You Should Know About the Sequel to Chickenpox

For an informative, accessible discussion on shingles — that you can listen to just about anywhere — check out an episode of this podcast from Cleveland Clinic's Health Essentials podcast.

Learn More About Additional Resources and Support for Shingles