Left untreated, shingles usually resolves on its own within two to four weeks, but the risk of serious, lasting complications rises sharply without antiviral medication. The most common consequence is chronic nerve pain that can persist for months or years. Depending on where the rash appears, untreated shingles can also cause vision loss, facial paralysis, hearing problems, and a temporarily elevated stroke risk.
How Shingles Progresses Without Treatment
Shingles follows a fairly predictable course. Pain, tingling, or itching begins several days before any visible rash. Some people also develop a fever during this early phase. The rash then appears, most often as a single stripe of blisters wrapping around one side of the body or face. Those blisters typically scab over in 7 to 10 days and clear within 2 to 4 weeks.
Without antivirals, this timeline doesn’t change dramatically for the rash itself. The blisters still heal. What changes is what happens afterward: the virus does more damage to the nerves while it’s active, and that nerve damage is where the real problems start.
Chronic Nerve Pain (Postherpetic Neuralgia)
The most common complication of untreated shingles is postherpetic neuralgia, or PHN: persistent pain in the area where the rash was, lasting long after the skin has healed. The pain can feel like burning, stabbing, or deep aching, and even light touch on the affected skin can be excruciating.
The difference treatment makes is striking. In a study published in BMC Infectious Diseases, 18.6% of patients who didn’t receive antivirals during their shingles episode still had nerve pain a year later, compared to just 2.6% of those who were treated. That’s a sevenfold difference. Among patients over 65, the average duration of postherpetic neuralgia was 3.3 years, with some cases lasting more than a decade. The median duration across all ages was about 9 months, though women tended to experience pain longer than men (12 months versus 6 months on average).
Your risk of developing PHN increases with age. About half of all shingles cases occur in adults 60 and older, and the chance of both getting shingles and developing lasting nerve pain rises steeply after age 70.
Vision Loss From Shingles Near the Eye
When shingles affects the branch of nerves serving your forehead and eye, it’s called herpes zoster ophthalmicus. This is one of the situations where skipping treatment carries the steepest consequences. Up to 50% of untreated patients with shingles in this area develop eye complications, including corneal damage that can permanently affect vision. With antiviral treatment, that rate drops to roughly 2%.
The cornea is especially vulnerable. The virus can destroy the nerve supply to the corneal surface, leaving it unable to sense irritation or heal properly. This condition, called neurotrophic keratitis, can lead to chronic ulcers, scarring, and progressive vision loss. If your shingles rash is on your forehead, the tip of your nose, or near your eye, those blisters signal that the virus is active in the same nerve branch that serves the eye, and treatment becomes urgent.
Facial Paralysis and Hearing Loss
Shingles affecting the ear and facial nerve can trigger Ramsay Hunt syndrome, a condition characterized by facial paralysis on one side, severe ear pain, and blisters in or around the ear canal. Some patients also experience hearing loss, ringing in the ears, vertigo, changes in taste, or difficulty swallowing.
The facial paralysis from Ramsay Hunt syndrome recovers less reliably than other types of facial nerve problems. Only about 70% of patients regain normal or near-normal facial movement, compared to over 90% recovery in Bell’s palsy. Without early antiviral treatment, the odds of full recovery are lower. The virus can also spread to the nerve responsible for hearing and balance, making the combination of symptoms unpredictable and sometimes severe.
Stroke Risk in the Weeks After Shingles
One of the lesser-known consequences of shingles is a temporary increase in stroke risk. Within 30 days of a shingles infection, patients have roughly 1.9 times the normal likelihood of experiencing a stroke. The virus can inflame blood vessels, particularly those supplying the brain, which is the mechanism behind this elevated risk. The danger is highest in the first month and gradually declines over the following year.
Rare but Serious Neurological Complications
In uncommon cases, the virus can spread to the brain and spinal cord, causing meningitis (inflammation of the membranes surrounding the brain) or encephalitis (inflammation of the brain itself). These infections are more frequent in people with weakened immune systems, but they can occur in otherwise healthy individuals. A Swedish study found an annual rate of about 1.8 cases of these central nervous system infections per 100,000 residents. In people with HIV, the incidence jumps dramatically to 29.4 per 1,000 person-years compared to 2 per 1,000 in the general population.
The outcomes can be significant. Up to 50% of patients with shingles-related meningitis still had neurological symptoms a month later. Among those with encephalitis, 18% experienced lasting problems including cognitive impairment, difficulty speaking, or seizures.
Separately, shingles can damage the motor nerves that control muscle movement. Peripheral nerve involvement occurs in 5% to 30% of patients, and muscle weakness or segmental paralysis appears in up to 7% of those with a visible rash. This can affect the arms, legs, or trunk depending on which nerves the virus attacks.
Bacterial Infection of Open Blisters
Shingles blisters are open wounds, and without proper care they can become infected with bacteria. This secondary infection can cause cellulitis (spreading skin infection), deeper tissue damage, or scarring that wouldn’t have occurred from the shingles alone. Keeping the rash clean and covered reduces this risk, but the longer blisters remain open, particularly in people with weakened immune systems or diabetes, the greater the chance of bacterial complications.
Why the First 72 Hours Matter
Antiviral medications work best when started within 72 hours of the rash appearing. In clinical trials, patients who received antivirals within 48 hours saw their pain resolve in a median of 28 days. Those given a placebo took 62 days to reach the same point. Even starting treatment in the 48 to 72 hour window still cut pain duration roughly in half.
After 72 hours, antivirals become less effective but aren’t necessarily pointless, especially if new blisters are still forming, if the rash involves the eye or ear, or if you’re immunocompromised. The window matters most for preventing postherpetic neuralgia and the serious organ-specific complications. Once nerve damage is established, it’s much harder to reverse.
For most healthy adults under 50, untreated shingles will be a painful but temporary experience. For anyone older, immunocompromised, or with shingles on the face, the gap between treated and untreated outcomes is large enough that early intervention can be the difference between a few weeks of discomfort and years of chronic pain or permanent damage.