Polio, or poliomyelitis, is a disease that spreads from person to person. It is caused by the poliovirus. The virus attacks the nervous system. In serious cases, it can cause paralysis (where you can't move parts of the body). The paralysis may be lifelong and can sometimes be life-threatening.

Because of vaccines, polio is rare in the United States. But polio does occur in some parts of the world, and travelers can spread the virus.

The poliovirus is very contagious. It spreads through contact with:

• The stool (poop) of person who has the infection
• Droplets from a sneeze or cough of someone who has the infection

This contact can happen if:

• You get contaminated stool or droplets on your hands and then touch your mouth
• A child puts contaminated toys or other objects into their mouth
• You share food or utensils with someone who has the infection

People who have the infection can spread it to others just before and up to several weeks after the symptoms appear. People who don't have symptoms can still spread the virus to others and make them sick.

Polio mainly affects children under age 5. But people of any age (including adults) who are unvaccinated are at risk of developing polio. People who live in or travel to areas where there is polio are more likely to get polio.

Most people who get infected with poliovirus do not have any symptoms. But one out of four people who get polio will have flu-like symptoms. These symptoms usually last 2 to 5 days, and they include:

• Sore throat
• Fever
• Fatigue
• Nausea
• Headache
• Stomach pain

In rare cases, polio can be very serious. It can lead to:

• Meningitis, an infection of the covering of your spinal cord and/or brain.
• Weakness or paralysis in your arms, legs, or both. This paralysis or weakness can last a lifetime. It is possible for the paralysis to become life-threatening if it affects the muscles that you use to breathe.
• Post-polio syndrome (PPS), which happens later in life.

Post-polio syndrome (PPS) is a condition that affects polio survivors many years after they recovered from polio. It usually happens 15-40 years later. It is not contagious.

People who get PPS start having new weakening in muscles that were previously affected by the polio infection. Symptoms may range from mild to serious. The symptoms of PPS include:

• Muscle weakness
• Muscle atrophy (wasting away of muscles)
• Loss of muscle function
• Mental and physical fatigue
• Joint pain
• Curving of the spine (scoliosis)

PPS is rarely life-threatening, but the symptoms can interfere with your daily life.

If you think you or someone in your family has symptoms of polio, call your healthcare provider right away or go to an emergency room.

To find out if you or your child has polio, the provider:

• Will do a physical exam.
• Will take a detailed medical history, including your vaccination history and history of any recent travel.
• Will collect samples of body fluids, such as stool, saliva, blood, urine, and spinal fluid. Poliovirus is most likely to be detected in stool specimens.
• May do an MRI to look at pictures of the spinal cord.

There is no cure or specific treatment for polio. For a mild case, getting rest and drinking plenty of liquids may help with some of the symptoms.

If the polio is more serious, you or your child may need:

• Physical or occupational therapy to help with arm or leg weakness. The earlier therapy is started, the better.
• Pain relievers to help with pain and treat fever. If your child is sick, do not give them aspirin unless their provider tells you to.
• A ventilator to help with breathing if the breathing muscles are weak or paralyzed.

There is no cure for PPS. Treatments may help you manage your symptoms. They include:

• Non-fatiguing exercises (exercises that do not cause pain or fatigue that lasts more than 10 minutes). These exercises may improve muscle strength and reduce tiredness. Your provider can help you figure out which exercises are best for you.
• Mobility aids.
• Ventilation equipment.
• Lifestyle changes, such as eating a healthy diet, getting enough sleep, and not smoking.

There are two types of vaccine that can prevent polio:

• Inactivated poliovirus vaccine (IPV) given as an injection in the leg or arm, depending on how old you are. Since 2000, this has been the only polio vaccine used in the United States.
• Oral poliovirus vaccine (OPV) is given as drops in the mouth. It is still used throughout much of the world.

Children in the United States get four doses of PV as part of their routine childhood immunizations. Most adults in the United States were vaccinated against polio as children.

There is a one-time IPV booster. It may be given to adults who have completed their polio vaccinations but are at higher risk of contact with poliovirus. You may be at higher risk if you are:

• Traveling to a country where the risk of getting polio is greater
• Working in a laboratory or healthcare setting and handling samples that might contain polioviruses
• A healthcare worker who has contact with patients who could have polio

Another way to help prevent the spread of polio is to wash your hands often with soap and water. Alcohol-based hand sanitizers will not kill poliovirus.

Centers for Disease Control and Prevention

Reye syndrome is a rare illness that can affect the blood, liver, and brain of someone who has recently had a viral infection. It always follows another illness. Although it mostly affects children and teens, anyone can get it. It can develop quickly and without warning. It is most common during flu season. Symptoms include:

• Nausea and vomiting
• Listlessness
• Personality change - such as irritability, combativeness or confusion
• Delirium
• Convulsions
• Loss of consciousness

If these symptoms occur soon after a viral illness, seek medical attention immediately. Reye syndrome can lead to a coma and brain death, so quick diagnosis and treatment are critical. Treatment focuses on preventing brain damage. There is no cure.

The cause of Reye syndrome is unknown. Studies have shown that taking aspirin increases the risk of getting it. Because of that, health care professionals now recommend other pain relievers for young patients.

NIH: National Institute of Neurological Disorders and Stroke

Smallpox is a disease caused by the Variola major virus. Some experts say that over the centuries it has killed more people than all other infectious diseases combined. Worldwide vaccination stopped the spread of smallpox three decades ago. The last case was reported in 1977. Two research labs still keep small amounts of the virus. Experts fear bioterrorists could use the virus to spread disease.

Smallpox spreads very easily from person to person. Symptoms are flu-like. They include:

• High fever
• Fatigue
• Headache
• Backache
• A rash with flat red sores

There is no treatment. Fluids and medicines for pain or fever can help control symptoms. Most people recover, but some can die. Those who do recover may have severe scars.

The U.S. stopped routine smallpox vaccinations in 1972. Military and other high-risk groups continue to get the vaccine. The U.S. has increased its supply of the vaccine in recent years. The vaccine makes some people sick, so doctors save it for those at highest risk of disease.

Your throat is a tube that carries food to your esophagus and air to your windpipe and larynx (also called the voice box). The technical name for the throat is pharynx.

You can have a sore throat for many reasons. Often, colds and flu cause sore throats. Other causes can include:

• Allergies
• Mononucleosis
• Smoking
• Strep throat
• Tonsillitis

Treatment depends on the cause. Sucking on lozenges, drinking lots of liquids, and gargling may ease the pain. Over-the-counter pain relievers can also help, but children should not take aspirin.

Your liver is the largest organ inside your body. It helps you digest food, store energy, and remove harmful substances (toxins). Steatotic liver disease, formerly called fatty liver disease, happens when too much fat builds up in your liver. It's typical to have some fat in your liver cells, but too much can be a problem.

There are two main types of steatotic liver disease:

• Metabolic dysfunction-associated steatotic liver disease (MASLD)
• Alcohol-associated liver disease (ALD)

MASLD is a type of steatotic liver disease that is not caused by heavy alcohol use. It used to be called nonalcoholic fatty liver disease. There are two main forms:

• Simple fatty liver, in which you have fat in your liver but little or no inflammation or liver damage. This form usually does not get bad enough to cause liver damage or complications.
• Metabolic dysfunction-associated steatohepatitis, or MASH (previously called nonalcoholic steatohepatitis or NASH), is when MASLD gets worse. In addition to fat in your liver, MASH may cause inflammation and liver damage. This can lead to fibrosis, or scarring, of the liver. This scarring sometimes leads to cirrhosis or liver cancer.

ALD is caused by heavy alcohol use. It used to be called alcoholic fatty liver disease, or alcoholic steatohepatitis.

Your liver breaks down most of the alcohol you drink, so it can be removed from your body. But the process of breaking it down can create harmful substances. These substances can damage liver cells, cause inflammation, and weaken your body's natural defenses. The more alcohol that you drink, the more you damage your liver. ALD is the earliest stage of alcohol-related liver disease. The next stages are alcoholic hepatitis and cirrhosis.

The cause of MASLD is unknown, but it is more common in people who:

• Have type 2 diabetes and prediabetes
• Have obesity
• Are middle aged or older (although children can also get it)
• Have high cholesterol or triglycerides
• Have high blood pressure
• Take certain medicines, such as corticosteroids and some cancer medicines
• Have certain metabolic disorders, including metabolic syndrome
• Have rapid weight loss
• Have certain infections, such as hepatitis C
• Have been exposed to certain harmful substances

MASLD is the most common chronic (long-term) liver disease due to increasing rates of obesity, type 2 diabetes, and high cholesterol.

ALD only happens in people who are heavy drinkers, especially those who have been drinking for a long period of time. The risk is higher for people who drink heavily and are women, have obesity, or have certain gene changes (known as variants or mutations).

Both MASLD and ALD usually have few or no symptoms. If you do have symptoms, you may feel tired or have discomfort in the upper right side of your abdomen (belly).

Because there are often no symptoms, it's not easy to find steatotic liver disease. Your health care provider may suspect you have it if you have abnormal results on liver tests. To make a diagnosis, your provider may use:

• Your medical history. This may include asking about your alcohol use and any medicines you take.
• A physical exam. This may include checking your height and weight. Your provider may also check your body for signs of liver disease such as an enlarged liver or jaundice, a condition that causes your skin and whites of your eyes to turn yellow.
• Blood tests. These may include liver function tests and blood count tests.
• Imaging tests. These tests may be used to check for fat in the liver and for fibrosis.
• A biopsy. In some cases, a biopsy may be done to confirm the diagnosis and check for liver damage.

The first step in treating MASLD is usually weight loss. Losing weight can reduce fat in the liver, inflammation, and fibrosis. If your provider thinks that a certain medicine is the cause of your MASLD, they may tell you to stop or switch medicines. But don't stop taking any medicines unless your provider tells you to.

More studies are needed to see whether certain medicines are safe and effective to treat MASLD. Currently, no medicines are approved for treatment.

The most important part of treating ALD is to stop drinking alcohol. If you need help, you may benefit from counseling, a recovery program, or medicines that reduce cravings or make you feel sick if you drink alcohol.

Both ALD and one type of MASLD can lead to cirrhosis. Health problems caused by cirrhosis may be treated with medicines, surgery, and other medical procedures. If cirrhosis leads to liver failure, you may need a liver transplant.

If you have any type of steatotic liver disease, there are some lifestyle changes that can help:

• Eat a healthy diet, limiting salt and sugar, plus eating lots of fruits, vegetables, and whole grains.
• Talk with your provider about vaccinations. If you have chronic liver disease you are more likely to get infections. Your provider may recommend vaccinations for hepatitis A and B, the flu and pneumococcal disease.
• Get regular exercise, which can help you lose weight and reduce fat in the liver.

Check with your provider before using dietary supplements, such as vitamins, or any complementary or alternative medicines or medical practices. Some supplements or herbal remedies can damage the liver.