Asthma symptoms vary from person to person. You may have infrequent asthma attacks, have symptoms only at certain times — such as when exercising — or have symptoms all the time.

Asthma signs and symptoms include:

• Shortness of breath
• Chest tightness or pain
• Trouble sleeping caused by shortness of breath, coughing or wheezing
• A whistling or wheezing sound when exhaling (wheezing is a common sign of asthma in children)
• Coughing or wheezing attacks that are worsened by a respiratory virus, such as a cold or the flu

Signs that your asthma is probably worsening include:

• Asthma signs and symptoms that are more frequent and bothersome
• Increasing difficulty breathing (measurable with a peak flow meter, a device used to check how well your lungs are working)
• The need to use a quick-relief inhaler more often

For some people, asthma signs and symptoms flare up in certain situations:

• Exercise-induced asthma, which may be worse when the air is cold and dry
• Occupational asthma, triggered by workplace irritants such as chemical fumes, gases or dust
• Allergy-induced asthma, triggered by airborne substances, such as pollen, mold spores, cockroach waste or particles of skin and dried saliva shed by pets (pet dander)

It isn't clear why some people get asthma and others don't, but it's probably due to a combination of environmental and genetic (inherited) factors.

Asthma triggers

Exposure to various irritants and substances that trigger allergies (allergens) can trigger signs and symptoms of asthma. Asthma triggers are different from person to person and can include:

• Airborne substances, such as pollen, dust mites, mold spores, pet dander or particles of cockroach waste
• Respiratory infections, such as the common cold
• Physical activity (exercise-induced asthma)
• Cold air
• Air pollutants and irritants, such as smoke
• Certain medications, including beta blockers, aspirin, ibuprofen (Advil, Motrin IB, others) and naproxen (Aleve)
• Strong emotions and stress
• Sulfites and preservatives added to some types of foods and beverages, including shrimp, dried fruit, processed potatoes, beer and wine
• Gastroesophageal reflux disease (GERD), a condition in which stomach acids back up into your throat

A number of factors are thought to increase your chances of developing asthma. These include:

• Having a blood relative (such as a parent or sibling) with asthma
• Having another allergic condition, such as atopic dermatitis or allergic rhinitis (hay fever)
• Being overweight
• Being a smoker
• Exposure to secondhand smoke
• Exposure to exhaust fumes or other types of pollution
• Exposure to occupational triggers, such as chemicals used in farming, hairdressing and manufacturing

Asthma complications include:

• Signs and symptoms that interfere with sleep, work or recreational activities
• Sick days from work or school during asthma flare-ups
• Permanent narrowing of the bronchial tubes (airway remodeling) that affects how well you can breathe
• Emergency room visits and hospitalizations for severe asthma attacks
• Side effects from long-term use of some medications used to stabilize severe asthma