Asthma attacks occur when an allergen (a substance the body perceives as a threat, triggering an allergic reaction) or irritant triggers an exaggerated response in a person with asthma (chronically sensitized or inflamed airways). Shortness of breath, chest tightness, coughing and wheezing (a whistling or high-pitched sound that results when breathing tubes are narrowed or obstructed) are among the symptoms that appear as the airways constrict and air becomes trapped in the lungs.

An asthma attack targets the body’s bronchial tubes, which bring oxygen to the lungs when a person inhales and remove carbon dioxide from the body when a person exhales. The diameter of these tubes narrows dramatically during an asthma attack due to a combination of factors, including:

• Inflammation and swelling of the lining of the tube
• Mucus buildup in the tube
• Smooth-muscle tightening around the tube

As a result, the person is less able to move air into and out of the lungs. A person experiencing an asthma attack must immediately take prescribed medication such as an inhaled bronchodilator or an injection of epinephrine contained in an allergy kit. The longer an attack continues, the greater the risk of severe health consequences. People experiencing an asthma attack who do not have medication or have symptoms that are not relieved with medication should seek immediate emergency medical care.  In rare cases, asthma attacks can be fatal.

Asthma attacks occur when a person with asthma (chronically sensitized or inflamed airways) is exposed to an allergen (a substance the body perceives as a threat, triggering an allergic reaction) or irritant that triggers a severe reaction. The airways constrict and begin to shut down, leading to symptoms such as shortness of breath, chest tightness, coughing and wheezing (a whistling or high-pitched sound that results when breathing tubes are narrowed or obstructed). Left untreated, an asthma attack can be fatal.

To understand how an asthma attack unfolds, it is important to know what takes place when a person breathes. Air is breathed in through the nose and mouth, and travels down past the vocal cords (larynx) through the windpipe (trachea). The bottom of the windpipe divides into left and right bronchi, the major air tubes that lead into the right and left lungs. The air continues on through the bronchi, which keep branching off like tree limbs into smaller and smaller air tubes known as bronchioles.

Eventually, these branches empty into millions of air sacs called alveoli. It is in the alveoli that the inhaled air finally crosses through tiny blood vessels called capillaries and into the bloodstream. Air travels through the blood to supply the cells with the oxygen they need to perform their work in the body. Meanwhile, the cells give up carbon dioxide into the blood, which transports it back to the alveoli. The carbon dioxide then moves into the lungs, where it is breathed out when a person exhales. 

A person without asthma has bronchial tubes with very thin walls that are surrounded by very loose smooth muscle. This allows the airways to open wide, making it easy for air to travel in and out.

However, the airways of a person with asthma are chronically inflamed and highly sensitive to allergens or irritants. Substances that would cause no problems in most people trigger a reaction in the lungs of people with asthma. This is a condition known as hyperreactivity. When the body is exposed to these triggers, it reacts by shutting down the bronchioles. The inner lining of the bronchial tubes, called the bronchial mucosa, contains two key elements involved in an asthma attack:

• Mucous glands. These usually produce just the right amount of mucus to keep the airways lubricated. However, during an asthma attack they produce too much mucus – flooding and blocking the airways.
  
  
• A group of cells – including eosinophils, lymphocytes and mast cells – known as “inflammatory cells.” These cells trigger inflammation in response to something the body perceives as a threat, such as allergens or irritants. The inflammation, in turn, allows for more blood to flow to the area, carrying cells to fight the threat. This is a natural system designed to protect body tissue, such as the lining of the bronchial tubes (mucosa). However, during an asthma attack, the tissues remain inflamed for extended periods of time.

The asthma attack begins when the immune system senses the triggering factor – which can be anything from pollen and latex to tobacco smoke and cold air – and overreacts in an attempt to protect the body. The inflammatory cells, which normally fight infections, rush into the lungs in what is known as an “inflammatory cascade.” 

These cells then release histamine, leukotrienes and other chemicals that cause the tissue in the bronchioles to become red, irritated and inflamed, which narrows the diameter of the airway in a process known as bronchoconstriction. As the tissues swell, they produce excess mucus that clumps together to form plugs that further clog the bronchioles.

Meanwhile, chemical mediators and nerves in the bronchial tubes cause the muscles surrounding the bronchioles to tighten in a process known as bronchospasm. This further narrows the airway inside, making it very difficult for air to travel through it. Although the people experiencing an asthma attack feel like they cannot breathe in enough air, in reality they cannot properly exhale, leaving air trapped inside the lungs. 

Every day 30,000 people across America have an asthma attack, according to the American Academy of Allergy, Asthma & Immunology. The factors that spark an asthma attack may be different for each person with the disorder. For some people, exposure to a single allergen is enough to induce an attack. Others need to be exposed to several triggers at the same time before they react.

Asthma attacks may start suddenly, or they may take days to develop. The severity of an attack also varies. Attacks can be mild, moderate or severe.

Left untreated, an asthma attack can cause additional damage. The alveoli (air sacs at the end of air passageways in the lungs) may rupture, causing air to gather in the space between the membrane layers that cover the lungs (pleural space) or allowing air to collect around the organs in the chest. This exacerbates shortness of breath. If left to progress, an asthma attack can turn fatal.

Occasionally, a second attack can occur about four hours after the initial exposure to the allergen or irritant that triggered the initial attack.  Secondary attacks may occur when changes develop in the patient’s air tubes. The lungs can become more sensitive to irritants after an initial asthma attack, leading to another attack. Symptoms of this reaction can last for several hours or even weeks after the first attack. Additional recurrent attacks can also follow, often at night.

An asthma attack involves only the bronchial tubes (large air passageways which bring oxygen to the lungs and remove carbon dioxide from the body during breathing). The air sacs and lung tissue are not affected by asthma. As these bronchial tubes repeatedly become inflamed with each new asthma attack, the walls can become permanently thickened in a process known as airway remodeling. This is dangerous because it makes the bronchioles (small air passageways within the lungs) less responsive to medications designed to keep the airways open.

Symptoms of an asthma attack vary from person to person and depend upon the nature and severity of the reaction. Signs and symptoms often associated with asthma attacks include:

• Wheezing (a whistling or high-pitched sound that results when breathing tubes are narrowed or obstructed)
  
• Shortness of breath
• Chest tightness or pain
• Coughing (with or without mucus)
• Difficulty speaking
• Extreme fatigue

An acute asthma attack is a sudden reaction to an allergen or an upper respiratory infection such as a cold. Such asthma attacks are potentially fatal because they often do not respond to quick-relief medications such as inhaled bronchodilators.

These severe attacks are known as “status asthmaticus.” Symptoms include:

• Persistent coughing, or – conversely – absence of coughing and wheezing. The latter is a very dangerous condition sometimes called “silent chest.” It indicates that the bronchial tubes (large air passageways which bring oxygen to the lungs and remove carbon dioxide from the body during breathing) are too clogged to allow those symptoms to manifest.
  
  
• Inability to speak full sentences or to walk without feeling shortness of breath
  
  
• Bluish tint to lips (cyanosis)
  
  
• Tight chest
  
  
• Sucking in of the skin between the ribs when breathing (occurs most often in children)
  
  
• Agitation, confusion and inability to concentrate

Such symptoms are a warning of impending respiratory failure. Patients who experience a sudden attack that does not resolve despite inhaler use should immediately head to the emergency room. A medical ventilator may be necessary to keep the lungs and respiratory muscles functioning and prevent death.

A patient who arrives at an emergency room or other healthcare facility and complains of an asthma attack will undergo a quick examination during which a nurse or physician will:

• Listen for breath sounds, particularly wheezing (a whistling or high-pitched sound that results when breathing tubes are narrowed or obstructed). The absence of wheezing may indicate severe bronchoconstriction, a condition known as “silent chest” that can be extremely dangerous.
  
  
• Note the patient’s rate of breathing and other physical signs. These include observing whether or not the patient is using additional muscles to help with breathing.
  
  
• Perform a pulse oximetry test. This is a painless procedure during which a probe is attached to the patient’s fingertip or earlobe to measure the amount of oxygen in the blood.
  
  
• Take readings of the patient’s blood pressure and pulse.

A physical examination and brief medical history will follow. Medications will not be given until a physician is absolutely sure the patient has no other conditions that might cause administration of a drug to harm the patient. The patient may receive oxygen, and an asthma medication designed to quickly open airways and ease breathing.  

Other tests that may be performed include:

• Chest x-ray. A physician may request this to check for coexisting medical conditions, such as an upper respiratory infection or pneumonia.
  
  
• Arterial blood gas test. A blood sample is taken from an artery, usually in the wrist. This sample is then used to measure the levels of both oxygen and carbon dioxide in the blood. As an asthma attack progresses, oxygen levels in the blood drop while carbon dioxide increases. Too much carbon dioxide buildup in the blood can be dangerous, and requires immediate treatment.

In order to keep their asthma under control, patients should know exactly what to do when asthma symptoms appear. They should know the warning signs of an attack and understand how to react when symptoms get worse.

Every asthmatic should have an asthma action plan. Created by a physician, these plans help guide the patient through an attack. The patient should follow the instructions of the asthma action plan when symptoms begin to appear. When treated promptly, most asthma attacks can quickly be brought under control.

A typical plan many unfold as follows:

• Patients experiencing an asthma attack will take their “reliever” medication designed to stop and reverse an asthma attack. This is different from a "controller" medication, which patients take regularly to prevent symptoms from appearing in the first place.
  
  The goal is to stop and reverse the process of narrowing of the airways as quickly as possible. Such medications include:
  
  
• • Beta agonists. Inhaled short-acting beta2 agonists are bronchodilators that reverse the symptoms of an asthma attack by relaxing the smooth muscle around the bronchial tubes.
    
    
  • Anticholinergics. These bronchodilator drugs also relax smooth muscle, but do so by affecting a different set of nerves than those impacted by beta agonists. When the two drugs are used together, it may enhance treatment of symptoms.
    
    
  • Corticosteroids. These drugs are powerful anti-inflammatories that are either inhaled, taken orally or injected. They reduce inflammation and help prevent recurrence of attacks.
    
    
  • Epinephrine (adrenaline). In cases of severe asthma attacks, an injection of epinephrine may be necessary to immediately reverse symptoms. Most often, this will be performed by a medical professional.
    
    
• After taking their medication, patients should cough to loosen mucus in the airways.
  
  
• Patients should then try to relax their breathing as much as possible.
  
  
• If symptoms do not subside, patients should seek immediate medical attention.

After an asthma attack has been brought under control, a physician will create a treatment plan designed to treat the asthma that is the underlying cause of the symptoms. Asthma treatments have two goals:

• To control airway inflammation in an attempt to make the airways less sensitive to allergen and irritant triggers.
  
  
• To prevent airway remodeling. In effect, this is achieved by successfully achieving the first goal.

Preparing questions in advance can help patients to have more meaningful discussions with their physicians regarding their conditions. Patients may wish to ask their doctors the following questions related to asthma attacks:

1. What tests will be used to determine if I have suffered an asthma attack?
   
   
2. What happens during an asthma attack?
   
   
3. How will I know when an asthma attack is occurring?
   
   
4. What risks are associated with asthma attacks?
   
   
5. What may be triggering my asthma attacks?
   
   
6. What steps can I take to prevent an asthma attack?
   
   
7. What treatments area available to me?
   
   
8. How should I react when I feel an attack coming on?
   
   
9. What steps should I take following an asthma attack?
   
   
10. When does an asthma attack require a visit to the emergency room?
    
    
11. Can I expect all of my future asthma attacks to have the same degree of severity?