Shingles is a painful, blistering rash caused by the same virus that causes chickenpox. After you recover from chickenpox, the virus doesn’t leave your body. It retreats into nerve cells near the spine and brain, where it can sit quietly for decades before reactivating as shingles. About 1 in 3 people in the United States will develop shingles at least once in their lifetime.
Why the Virus Reactivates
The virus behind both chickenpox and shingles is varicella zoster. During a childhood chickenpox infection, the virus travels along nerve fibers and settles into clusters of nerve cells called ganglia. There, it enters a dormant state, with only a handful of viral copies (roughly 2 to 9 per cell) tucked inside about 4% of neurons. The virus essentially goes silent: it stops replicating and stops producing the proteins it needs to spread.
For years or even decades, your immune system keeps the virus in check. Reactivation happens when that surveillance weakens. The exact cellular trigger is still unknown, but the pattern is clear: shingles is far more common in people over 50, whose immune defenses naturally decline with age, and in people with weakened immune systems from conditions like cancer, HIV, or immunosuppressive medications. Severe stress, major surgery, and illness can also tip the balance.
When the virus wakes up, it travels back down the nerve fiber to the skin, causing inflammation along the way. This is why the rash follows a specific nerve pathway and typically appears on just one side of the body.
What Shingles Looks and Feels Like
Shingles doesn’t start with a rash. Most people first notice a burning, tingling, or numb sensation on one side of the body or head. This early warning phase, called the prodrome, lasts 1 to 5 days and can include fever and general fatigue. The pain sometimes appears without any visible skin changes, which can make early diagnosis tricky.
Within days, a red rash appears in the area where the tingling started. That rash quickly develops into clusters of small, fluid-filled blisters. New blisters continue forming over 3 to 5 days, and the rash most commonly shows up on the trunk, wrapping around one side of the torso along a band-like strip. It can also appear on the face, neck, or scalp. A defining feature: it almost never crosses the body’s midline. If your rash is on the left side of your back, it stays on the left side.
The blisters are the most painful phase. They typically begin crusting over within 7 to 10 days of forming, and the scabs heal within about 2 weeks after that. The entire episode, from first tingle to cleared skin, usually resolves within 5 weeks.
Postherpetic Neuralgia: When Pain Lingers
The most common complication of shingles is nerve pain that persists long after the rash is gone. This is called postherpetic neuralgia, defined as burning or shooting pain in the affected area that lasts three months or more after the initial outbreak. The pain can range from a constant deep ache to sharp, stabbing sensations triggered by something as light as clothing brushing the skin.
About 13% of shingles patients aged 50 and older develop postherpetic neuralgia. The risk climbs steeply with age: roughly 60% of shingles patients at age 60 experience it, rising to 75% at age 70. For most people, the pain gradually fades over months. For some, it continues for years or, in rare cases, becomes permanent.
Shingles Near the Eye
When shingles affects the nerve branch that supplies the forehead and eye area, it can cause serious damage to your vision. The virus can trigger inflammation in every layer of the eye, including the cornea, retina, and the tissue lining the inside of the eyelid. Without prompt treatment, this inflammation can scar the eye and lead to permanent vision loss.
Warning signs include a painful rash on the forehead or around one eye, severe eye pain, swelling of the eyelid, redness, and sensitivity to light. Some people also notice tingling or pain in the face before any rash appears. If you develop a rash anywhere near your eye, getting evaluated quickly is critical because early treatment can prevent lasting damage.
Can You Spread Shingles to Others?
You cannot give someone shingles. However, if you have active blisters, you can spread the varicella zoster virus to someone who has never had chickenpox or the chickenpox vaccine. That person wouldn’t develop shingles directly but could develop chickenpox, and then carry the risk of shingles later in life. The virus spreads through direct contact with blister fluid or by breathing in virus particles released from open blisters.
You’re only contagious while the blisters are open and weeping. Once the rash has fully scabbed over, you can no longer spread the virus. Keeping the rash covered reduces the risk. During an active outbreak, it’s especially important to avoid contact with pregnant women who haven’t had chickenpox, newborns, and anyone with a compromised immune system.
Treatment and the 72-Hour Window
There’s no cure for shingles, but antiviral medications can shorten the illness, reduce its severity, and lower the chance of developing postherpetic neuralgia. These drugs work best when started within 72 hours of the rash first appearing, which is why recognizing the early signs matters so much. After that window, antivirals are less effective, though doctors may still prescribe them for severe cases or when the eyes are involved.
Beyond antivirals, treatment focuses on managing pain. Over-the-counter pain relievers help with mild cases. More severe pain may require stronger prescription options. Cool compresses and calamine lotion can soothe the skin. Most people recover at home without hospitalization.
Vaccination
The current shingles vaccine is given as two doses, spaced 2 to 6 months apart, and is recommended for adults 50 and older. People with weakened immune systems who would benefit from faster protection can receive the second dose as early as 1 to 2 months after the first. The vaccine is recommended even if you’ve had shingles before, since the disease can recur, and even if you don’t remember having chickenpox, since most adults raised before widespread chickenpox vaccination carry the virus.