Varicella-zoster is the virus that causes chickenpox. The illness clears up in a week or two, but the virus remains in your body.

When your immune system is healthy and strong, the virus stays inactive. If you become immunocompromised, meaning your immune system becomes weak, the virus can reactivate, triggering shingles.

Shingles, also known as herpes zoster, is a painful rash that occurs on one side of your body.

It’s caused by reactivation of the virus that causes chickenpox. According to the Centers for Disease Control and Prevention (CDC), there’s a 1 in 3 chance you’ll have shingles sometime in your life.

The first time you’re exposed to the varicella-zoster virus (VZV), you get chickenpox. As your body fights the virus, you develop immunity, so you very rarely get chickenpox again.

The virus becomes inactive but stays in your body the rest of your life. A strong immune system keeps the virus inactive, so it doesn’t cause any problems.

However, if your immune system becomes weakened, the virus can become active again. This time, it causes the painful rash known as shingles.

Before there was a varicella vaccine, most people were exposed to VZV and developed chickenpox during childhood.

This was encouraged, because after the age of 10 or so, chickenpox is a much more serious disease. Instead of the itchy rash seen children, adults who get chickenpox often develop severe, life threatening lung or brain infections.

Today, the varicella vaccine is given to young children and to adults who haven’t had chickenpox. It contains a weakened version of the live virus. Your body responds as if it’s the real virus and develops immunity to chickenpox.

Although it’s weakened, the virus can still become inactive and stay in your body. It can later reactivate and cause shingles, but the risk is extremely low.

In one study, the number of vaccinated children who got shingles was 78 percent lower than the number among unvaccinated children.

Since the vaccine has only been available since 1995, its effect on the rate of shingles in adults isn’t yet known.

Anyone who’s had chickenpox or received the chickenpox vaccine can get shingles.

The CDC estimates that over 99 percent of people in the United States born before 1980 have had chickenpox and have VZV in their bodies.

A weakened immune system is the main factor associated with getting shingles, because it allows VZV to reactivate.

Age is the factor most associated with the strength of the immune system. As you get older, you’re more likely to have one or more of the following things that weaken your immunity:

You’re most likely to get shingles if you’re 50 or older. In addition, disease severity and likelihood of complications increase with age starting around 50.

Stress can weaken your immune system. Some people think that there’s a link between experiencing a lot of stress and getting shingles. Researchers have studied this, but the results are contradictory, so they don’t know the answer yet.

Anyone who’s had chickenpox can develop shingles. While you can’t “catch” shingles, people who have never had chickenpox can develop it if they come into contact with the liquid from shingles blisters. Once their blisters have crusted over, a person with shingles is no longer contagious.

The classic symptom of shingles is a painful rash on the dermatome, an area of your skin mainly supplied by a single nerve. The rash has distinctive features, such as the following:

  • It appears as a band of blistering lesions on red, inflamed skin on one side of your torso or face.
  • The pain starts as a tingly or burning sensation, and you may also feel itchiness or numbness.
  • The pain typically becomes severe over the next few days.
  • You may think the pain is coming from organs located in the same area such as your heart, gallbladder, appendix, or kidney until the rash appears.
  • Rarely, severe pain can occur without a rash (zoster sine herpete).

Some people also have symptoms that aren’t specific to shingles, such as:

It may take 4 weeks or longer for your symptoms to go away.

Your doctor will ask you some questions, such as:

  • When did your symptoms start?
  • What did you notice first?
  • Are you experiencing pain?
  • Where is your pain located?
  • Have you had chickenpox?
  • Have you had the chickenpox vaccine?
  • Have you had the shingles vaccine?

They’ll evaluate your rash based on its

  • pattern
  • appearance
  • location

Usually your doctor can diagnose shingles based only on its distinctive rash and symptoms.

Rarely, when the diagnosis isn’t clear, your doctor will perform a shingles test. A test may also be done on those at high risk for complications, including:

  • people with a weakened immune system
  • pregnant women
  • newborns

Using a swab, your doctor will take a sample from a lesion which will be tested to see if VZV is present. If it is, you know you have shingles.

How to feel better if you have shingles

Here are some things you can do to help yourself feel better when you have shingles:

  • Stay healthy with a balanced diet, plenty of rest, and gentle exercise.
  • Soak in a bathtub containing lukewarm water and ground-up oatmeal to relieve pain and itchiness.
  • Apply a cool, wet washcloth or compress to the rash to reduce pain and help lesions crust over faster.
  • Avoid stress, which may weaken your immune system and make your symptoms worse.
  • Keep lesions covered with a bandage, and wear loose clothing to avoid irritating the rash.
  • Apply a thin layer of Vaseline to the rash before putting on a bandage to help reduce irritation.

Shingles can’t be cured, but it gets better on its own. Medications are often used to treat the infection and relieve pain.

Antiviral medication

Antiviral medication can help:

  • speed your recovery
  • reduce the severity of your symptoms
  • lower your risk of complications

People over 50 and those with weak immune systems benefit the most from antivirals, because they tend to have more persistent and severe symptoms.

Antivirals should be started while you’re still developing new lesions, which is usually within 72 hours of your first symptom. After the lesions start crusting over, antivirals are no longer effective.

There are three antivirals used for shingles:

Valacyclovir and famciclovir are taken 3 times a day. They’re usually recommended over acyclovir, which must be taken 5 times a day. All three are taken for 7 days if the shingles rash is on your torso.

You may need to take an oral antiviral longer or be treated in the hospital with IV antivirals if you have:

  • a weakened immune system
  • a severe case of shingles
  • a high risk of complications

Shingles on your face can cause serious complications, including:

  • blindness
  • hearing impairment
  • brain swelling

See your doctor right away if you think you have shingles on your face.

Pain medication

Over-the-counter (OTC) anti-inflammatory medication can be used for mild pain. These medications include ibuprofen or acetaminophen or weak opioids, such as codeine or tramadol.

Stronger prescription opioid pain medication, such as hydrocodone, is used for the moderate to severe pain shingles can cause.

Topical pain relievers that you apply directly to your skin include lidocaine, which comes as an ointment, cream, gel, spray, or patch, and capsaicin, which comes as a cream or patch.

Other medications that may be necessary include:

  • diphenhydramine
  • hydroxyzine
  • calamine lotion for itchiness
  • antibiotics, if a bacterial infection develops around the rash

There are currently two shingles vaccines available in the United States:

  • Shingress (recombinant zoster vaccine)
  • Zoatavax (zoster vaccine live)

They’re given to people over the age of 50.

Shingress is the preferred vaccine. While Zoatavax is still available, it’s being phased out. As of July 1, 2020, Zoatavax is no longer being sold, but existing doses may be used until the expiration date, which is November 2020.

For people over the age of 50, getting a shingles vaccine can lower the risk of getting shingles by about 50 percent, according to the CDC.

If you’ve been vaccinated and get shingles anyway, the symptoms will usually be less severe, and you’ll be less likely to get postherpetic neuralgia.

The course of a bout of shingles follows this pattern:

  • You usually notice a tingling or burning sensation in your skin first.
  • The rash typically starts as small red spots that show up 1 to 5 days later but may appear at the same time as the pain.
  • A few days later, fluid-filled blisters appear.
  • Seven to ten days later, the lesions crust over and disappear over the next 2 to 4 weeks.

Sometimes the pain persists for several months or years after the lesions have crusted over. This is called postherpetic neuralgia (PHN). It’s a complication of shingles in which the pain can be severe or even incapacitating.

The antiseizure medications gabapentin and pregabalin can help make the pain more tolerable.

Although it’s rare, you can get shingles more than once. That’s why you should get the shingles vaccine at age 50 or older if your immune system is strong, even if you’ve already had shingles.

It’s extremely rare to get shingles three times.

The painful blistering rash of shingles occurs when VZV reactivates during a time when your immune system is weakened. If you’re at a high risk for having a weakened immune system, you’re more likely to get the infection.

Your risk of getting shingles goes up as you get older, especially after age 50.

Shingles will get better on its own, but antiviral medication can speed your recovery and lower your risk of complications like PHN.