Asthma

Asthma is a common long-term disease that affects the airways in the lungs. It causes symptoms like wheezing, coughing, chest tightness, and shortness of breath. These symptoms can come and go and might get worse at night or when someone exercises.

Asthma happens because of a mix of genetic and environmental factors. Things like air pollution, allergens, dust, and pollen can trigger asthma symptoms. Sometimes medications can also make symptoms worse.

There is no cure for asthma, but it can be managed. People with asthma can avoid things that trigger their symptoms and use special medicines to keep them under control. If symptoms get very bad quickly, fast-acting medicines can help, and sometimes a hospital visit is needed.

Asthma affects millions of people around the world, and most cases start in childhood. It has been known since ancient times, with early mentions in Ancient Egypt.

Signs and symptoms

Asthma can cause episodes where a person may wheeze, feel short of breath, have a tight feeling in their chest, or cough. These symptoms often get worse at night, early in the morning, after exercising, or when exposed to cold air. Some people with asthma only have symptoms when something triggers them, while others may have symptoms more often and for longer periods.

Asthma is also often linked with other health issues. These can include allergies like pink eye or a runny nose, trouble breathing during exercise, trouble sleeping due to breathing problems, being overweight, stomach issues, diabetes, heart problems, and mental health concerns like feeling worried or sad.

Classification

Asthma is a group of similar symptoms and signs rather than one single disease. It used to be split into two types: one caused by things like allergies and another not linked to allergies. Today, doctors classify asthma mainly by how severe it is, how well symptoms are controlled, and by looking at different patterns and underlying causes.

Asthma can be hard to tell apart from a condition called chronic obstructive pulmonary disease (COPD), but they differ in how the breathing problems change over time. In asthma, breathing difficulties come and go, while in COPD, they usually get worse steadily.

The severity of asthma is judged by how much medicine someone needs to keep symptoms under control. Control is measured by how well symptoms are managed and the risk of future problems. Doctors look at how often symptoms occur, how much they affect daily life, use of rescue inhalers, and various tests to check lung function.

Asthma can also be grouped by how it shows up and what causes it. There are different patterns based on the body’s response to the disease, such as whether certain immune system markers are present. These patterns help doctors understand the disease better and guide treatment. An asthma exacerbation, often called an asthma attack, is when symptoms suddenly get worse, making it harder to breathe.

Causes

Asthma happens because of a mix of things you are born with and things around you in the world. If a person has a family history of asthma, they might get it too, especially if they are around certain things that can start the asthma.

Things that can make asthma more likely or worse include:

• Having a mother who was overweight, smoked, or was stressed during pregnancy
• Being around smoke, mold, or other bad air when you are very young
• Having infections in your lungs
• Living in a city with lots of pollution
• Being around things that can cause allergies, like dust or pets

Asthma can also start later in life because of jobs or other things you are around a lot. It affects more girls than boys when it starts as an adult. Many things together decide if someone will have asthma, including what they are born with and what they experience every day.

Pathophysiology

Asthma happens when the airways in the lungs get swollen and narrow. This is caused by muscles around the airways tightening, swelling inside the airways, and extra mucus being made. These changes make it hard for air to move in and out of the lungs.

The airways can get narrower after meeting things that trigger them, like dust or cold air. This narrowing can make breathing difficult, but treatments can help open the airways again.

Diagnosis

To find out if someone has asthma, doctors look at their symptoms and test how well their lungs work. They cannot just use one test; they need to see how the symptoms and lung function match up.

Doctors might ask about wheezing, shortness of breath, chest tightness, and coughing, especially if these change during the day or with certain triggers. They also check if the person or their family has a history of allergies. Tests like spirometry, which measures how much air a person can move in and out of their lungs, can help confirm asthma. Another test looks at how well the lungs work after using asthma medicine. If spirometry is not available, doctors might ask the person to measure their breathing speed twice a day for two weeks. Big changes in this speed can suggest asthma.

Other tests can also help, but they are not always sure. Sometimes, more detailed tests are needed, especially if the person is not getting better with treatment. For children under five, doctors might treat symptoms first before doing many tests.

Prevention

There are a few ways that may help prevent asthma in children. One way is to avoid using certain medicines called broad-spectrum antibiotics during a child's first year of life. It is also important to keep children away from tobacco smoke before and after they are born. Doctors recommend that mothers check and treat low levels of a vitamin called vitamin D during pregnancy. Having a baby delivered naturally, instead of through surgery, may also help.

Other ideas, like changing food, breastfeeding, taking extra vitamins, or letting children play with pets early, have not been proven to prevent asthma yet.

Management

The goal of asthma management is to help reduce symptoms and prevent problems like worsening of symptoms, trouble breathing, and side effects from medicine. This is done by checking how well asthma is controlled, giving advice on how to manage it, finding things that make symptoms worse, and using medicine. It is important to talk about asthma at doctor visits so treatment can be changed if needed.

After someone is told they have asthma, they and their family should learn about the disease and how to manage it. This includes learning how to avoid things that make symptoms worse, watching symptoms, having a plan for managing asthma, and knowing treatment choices. Plans for asthma help prevent and treat sudden worsening of symptoms and knowing when to get more help. Teaching school children about asthma helps reduce trips to the hospital.

Lifestyle changes

Ways to help manage asthma without medicine include staying away from things that make symptoms worse and taking care of health. Smoking and being around second-hand smoke can make asthma worse, so it is best to not smoke and stay away from smoke. At work, it is important to avoid things that can trigger asthma. Some medicines can make asthma symptoms worse in some people, but they can still be used unless they have caused problems before.

Having a healthy diet and doing regular exercise are good for overall health. Exercise does not make asthma symptoms better, but it is good for health. Sometimes exercise can make symptoms worse, so using an inhaler before exercise can help. Keeping a healthy weight also helps manage asthma better.

Medicines

Medicine for asthma comes in different types and ways to use them. Some medicines are taken every day to keep symptoms under control, while others are used when symptoms get bad. The way medicine is taken, like using an inhaler, depends on the type of medicine, what is available, and how easy it is to use.

The first type of medicine for children with asthma is a special inhaler that helps keep symptoms down. Everyone with asthma should also have a medicine to use when symptoms get worse. For older children and adults, a mix of two medicines in one inhaler is often recommended. If symptoms do not get better with these, more medicines might be added to help control them.

When asthma gets worse, special medicines and oxygen can help someone feel better. It is important to follow the plan made with a doctor to keep asthma under control and prevent it from getting worse.

Prognosis

Asthma usually has a good outlook, especially for children with mild cases. Over the years, fewer people have passed away from asthma because doctors now recognize it better and have improved treatments.

Many people around the world live with asthma, and it can sometimes make it hard for them to do everyday activities. However, for some children diagnosed with asthma, about half may no longer have asthma after ten years. Treatments can help keep lungs healthy and strong. It's also important to remember that asthma can affect not just the child but also their parents, who may feel worried or stressed.

Main article: Disability-adjusted life year for asthma per 100,000 inhabitants in 2004

Epidemiology

Main article: Epidemiology of asthma

In 2023, around 363 million people around the world had asthma. The number of cases differs from country to country, ranging from 1% to 29% of the population. It happens more often in wealthier countries than in poorer ones. For example, it is less common in parts of Asia, Eastern Europe, and Africa.

Asthma is slightly more common in boys than girls when they are young, but in adults, women are more likely to have it than men. Overall, asthma has been becoming more common since the 1960s, especially in poorer countries. Today, about 7% of people in the United States and 5% in the United Kingdom have asthma. Countries like Canada, Australia, and New Zealand have even higher rates, around 14–15%.

Health disparities

Asthma affects people differently depending on where they live and their background. In countries that are more urban and developed, asthma is more common than in less developed places, though this alone doesn't explain why some groups get it more often.

In the United States, children from certain racial and ethnic groups, like non-Hispanic Black and Puerto Rican children, have higher rates of asthma. Children from families with lower incomes also face a higher risk. Air pollution in some neighborhoods, especially those with more minority populations, can make asthma worse. These areas often have more pollution, which contributes to the disease.

Economics

From 2000 to 2010, the cost of hospital stays for children with asthma in the United States stayed around $3,600. For adults, the cost went up from $5,200 to $6,600. In 2010, Medicaid helped pay for most hospital stays for both children and adults aged 18–44 years. Private insurance was the second most common way to pay. In 2010, children and adults living in the lowest-income areas had more hospital stays for asthma than those in the highest-income areas.

History

Asthma has been known for thousands of years. Ancient Egyptians treated it by drinking a special incense mix. The Greek doctor Hippocrates named it around 450 BC, using a word that means "panting." Over time, many cultures found ways to help with asthma symptoms.

In the 19th century, famous leader Theodore Roosevelt had asthma as a child. Doctors then tried different treatments, like special rubs and medicines. By the early 1900s, scientists began understanding more about how to help people with asthma, using treatments like a natural hormone called epinephrine. In the 1930s, doctors started measuring how well people with asthma could breathe.

Later, new medicines were created that helped open the airways. By the 1960s, doctors had special inhalers that made these medicines easy to use. This helped many people manage their asthma better.