Polio

Medically Reviewed by Jabeen Begum, MD on March 22, 2024
Written by Stephanie Booth, Sarah Vanbuskirk
7 min read

Polio is short for "poliomyelitis." It's a virus that spreads easily between people who aren't vaccinated. If you get polio, you might have no symptoms or get flu-like symptoms. It’s less common, but the virus can make you very ill and cause you to lose the ability to move your limbs (paralysis). It could even kill you. People of any age who are not vaccinated can get polio, but kids under 5 have the highest risk.

Is polio eradicated?

Globally, polio cases have decreased by more than 99% since 1988. There are three types of poliovirus (type 1, type 2, and type 3). Two have been eradicated (meaning they no longer exist). Type 3 exists in only two countries: Pakistan and Afghanistan.

Polio has been around for thousands of years. Ancient Egyptian artwork shows images of children with deformed limbs walking with canes. It was first described by a doctor in 1789 and was officially called a disease in 1840. Outbreaks of polio often killed thousands of people. Many who survived ended up paralyzed or needing an iron lung -- a type of old-fashioned breathing machine -- to breathe. For centuries, polio was a feared disease.

In the 1950s, Dr. Jonas Salk created the first polio vaccine. At that time, polio paralyzed or killed over half a million people each year around the world. Once the vaccine was introduced, those numbers dropped quickly. In 2020, no one in the United States got polio. The disease is no longer actively spreading in most of the world.

Polio causes several types of illnesses:

Abortive polio. This is the mildest form. If you get it, you may have cold or flu symptoms and an upset stomach. Your brain is not usually impacted. Symptoms usually last for a few days to about a week.

Nonparalytic polio. This type is similar to abortive polio but the symptoms are more severe and may last longer. You are also at risk of getting meningitis, a serious condition that causes swelling around your brain. You may need to stay at the hospital while you recover.

Paralytic polio. This is the most severe type of polio. It can cause permanent weakness or paralysis of your legs, arms, or breathing muscles. 

Polioencephalitis. Infants are most likely to get this rare type of polio. It causes swelling of the brain.

Post-polio syndrome. Sometimes, polio symptoms like leg and arm weakness return years after your initial infection. This is called post-polio syndrome. It can happen to anyone who has had polio in the past, even if you fully recovered.

You get polio from a virus. You have to come in direct contact with the virus to get it. This can be person-to-person contact or through contact with an object that has the virus on it. When you have the virus, it lives in your throat and intestines.

How does polio spread?

The virus gets inside you through your mouth. You might get it by:

  • Contact with poop from a person with polio. This can include putting an object that has poop on it in your mouth or getting it on your hand and putting your hand in your mouth. Water or food that is contaminated with infected poop can also spread polio.
  • Breathing in droplets from a cough or sneeze of a person with polio. 

Even if you don’t have symptoms, you can pass on polio to others if it’s in your body.

 

Symptoms depend on the type of polio you have.

Abortive polio symptoms:

  • Fever
  • Headache
  • Muscle aches
  • Sore throat
  • Stomachache
  • Loss of appetite
  • Nausea
  • Vomiting

It's common not to have any symptoms with abortive polio.

Nonparalytic polio symptoms include more severe symptoms of abortive polio, plus: 

  • Pain and stiffness in your neck
  • Aches or stiffness in your arms or legs
  • Bad headache

There may also be a second phase of nonparalytic polio. After you have seemed to get better, you might have:

  • Spine and neck stiffness
  • Decreased reflexes
  • Muscle weakness

Paralytic polio symptoms:

  • A loss of reflexes
  • Severe muscle pain or weakness
  • Floppy limbs
  • A feeling of pins and needles in your legs
  • Paralyzed arms, legs, or both
  • Severe sensitivity to touch
  • Problems swallowing
  • Difficulty breathing

Symptoms of post-polio syndrome:

You're at risk of getting polio if you're unvaccinated. If you have been vaccinated, it is extremely rare for you to get it. Children under 5 are at higher risk of infection until they are fully vaccinated. You are also at risk if you are around someone who has polio or if you travel to a country where polio exists. 

Your doctor can tell if you have polio by checking your poop or throat for the poliovirus. They will take a small sample by swabbing your throat or collecting a sample of your poop. The sample is tested in a lab. Sometimes, they will check your spinal fluid. This is done with a spinal tap or lumbar puncture. In this test, a needle is inserted into your spinal canal to draw out a sample of fluid.

There's no cure for polio. If you have it, your doctor will focus on making sure that you're comfortable and try to prevent other health issues. Some treatments include:

  • Pain relievers (like ibuprofen)
  • A ventilator (a device that helps you breathe)
  • Physical therapy that can help keep your muscles working
  • Bed rest and fluids for flu-like symptoms
  • Antispasmodic medications to relax muscles
  • Antibiotics for urinary tract infections
  • A heating pad for muscle aches and spasms
  • Corrective braces
  • Pulmonary rehabilitation to help with lung complications
  • A mobility aid such as a cane, wheelchair, or electric scooter

 

A vaccine helps your body create substances called antibodies. These protect you from getting polio if you come in contact with the virus. 

There are two types of the vaccine:

Inactivated poliovirus vaccine (IPV). This is the vaccine that is used in the U.S. You get this as a shot in either your leg or your arm. It's a very safe vaccine that is 99% effective when you get the full series of doses. 

Oral poliovirus vaccine (OPV). This is an older form of the vaccine that’s still used in other parts of the world. It's given by mouth. It's very effective, but in rare cases it can cause an outbreak of polio. 

Today, kids in the U.S. get four doses of the IPV vaccine -- one dose each at ages:

  • 2 months
  • 4 months
  • Between 6 and 18 months
  • Between 4 and 6 years

If you're an adult who got the polio vaccine as a child, you should still be immune. The only reason you might need a booster shot is if you plan to travel to a country where polio is still common or you spend time with someone who has polio.

If you didn't have all your vaccines or are unsure, your doctor can give them to you. You'll get two shots that are 4 to 8 weeks apart, and then a third shot 6 months to a year later.

Polio vaccine reaction

Reactions to the vaccine are very rare. The most common is mild pain in the body part where you got the shot. It usually goes away quickly. A few people might have pain that is more severe and lasts longer.

All vaccines can cause an allergic reaction, but it's rare -- about 1 in a million people. Usually you’ll see any symptoms of an allergy within a few minutes to a few hours after you get it. To tell if you have an allergy to the polio vaccine, watch for:

Get medical care right away if you have any of these signs.

If you have been fully vaccinated, you are very unlikely to get polio even if you come in contact with it.

Polio spreads by person-to-person contact or by touching something that has the virus on it. It’s also important to wash your hands often with soap and warm water. Alcohol-based hand sanitizer does not kill the poliovirus. Discourage young kids from putting their fingers in their mouths.

If you are around someone with polio, try not to touch anything they have touched. Wash your hands if you do. Young children under 5 and anyone who is not vaccinated should avoid being near someone with polio. 

If you are traveling internationally to a place with polio outbreaks, use extra caution and be sure you and your family are fully vaccinated.

Polio can cause serious complications like paralysis or death. You can prevent polio by getting vaccinated and washing your hands frequently. Contact your doctor if you or your child needs the vaccine and to talk about any questions or concerns you have.

Can you recover from polio?

There is no cure for polio. If you have mild polio or no symptoms, you will most likely fully recover without treatment. However, you may develop symptoms like muscle weakness later in life. This is called post-polio syndrome. If you have a more severe form of polio, you may become paralyzed, have lasting breathing problems, or even die.

What does polio do to the legs?

Polio can cause muscle weakness or paralysis in your legs. Most often you will not have symptoms in your legs. But about 1 in 200 to 1 in 2,000 people end up paralyzed.

Is polio treatable?

There are no treatments to cure polio. The best way to fight it is to get the vaccine. If you have polio, you should rest, drink plenty of fluids, and let your doctor know about any muscle weakness, difficulty breathing, or any other concerning symptoms. Treating it early with physical therapy can help if you have leg or arm weakness. In severe cases, you might need aids like leg braces, crutches, or a wheelchair. A ventilator may be needed if you have trouble breathing.