Inflammation and narrowing of the airway in any location, from your throat out into your lungs, can result in wheezing.

The most common causes of recurrent wheezing are asthma and chronic obstructive pulmonary disease (COPD), which both cause narrowing and spasms (bronchospasms) in the small airways of your lungs.

However, any inflammation in your throat or larger airways can cause wheezing. Common causes include infection, an allergic reaction or a physical obstruction, such as a tumor or a foreign object that's been inhaled.

All of the following conditions can lead to wheezing:

• Allergies
• Anaphylaxis (a severe allergic reaction, such as to an insect bite or medication)
• Asthma — a long-term condition that affects airways in the lungs.
• Bronchiectasis (a chronic lung condition in which abnormal widening of bronchial tubes inhibits mucus clearing)
• Bronchiolitis (especially in young children)
• Bronchitis
• Childhood asthma
• COPD (chronic obstructive pulmonary disease) — the blanket term for a group of diseases that block airflow from the lungs — including emphysema.
• Emphysema
• Epiglottitis (swelling of the "lid" of your windpipe)
• Foreign object inhaled: First aid
• Gastroesophageal reflux disease (GERD)
• Heart failure
• Lung cancer
• Medications (particularly aspirin)
• Obstructive sleep apnea (a condition in which breathing stops and starts during sleep)
• Pneumonia — an infection in one or both lungs.
• Respiratory syncytial virus (RSV) — especially in young children
• Respiratory tract infection (especially in children younger than 2)
• Smoking
• Vocal cord dysfunction (a condition that affects vocal cord movement)

Wheezing is a high-pitched whistling sound made while breathing. It's often associated with difficulty breathing. Wheezing may occur during breathing out (expiration) or breathing in (inspiration).

Mild wheezing that occurs along with symptoms of a cold or upper respiratory infection (URI), does not always need treatment.

See a doctor if you develop wheezing that is unexplained, keeps coming back (recurrent), or is accompanied by any of the following signs and symptoms:

• Difficulty breathing
• Rapid breathing
• Briefly bluish skin color

Seek emergency care if wheezing:

• Begins suddenly after being stung by a bee, taking medication or eating an allergy-causing food
• Is accompanied by severe difficulty breathing or bluish skin color
• Occurs after choking on a small object or food

In some cases, wheezing can be relieved by certain medications or use of an inhaler. In others, you might need emergency treatment.

Self-care measures

To ease mild wheezing related to a cold or URI, try these tips:

• Moisturize the air. Use a humidifier, take a steamy shower or sit in the bathroom with the door closed while running a hot shower. Moist air might help relieve mild wheezing in some instances.
• Drink fluids. Warm liquids can relax the airway and loosen up sticky mucus in your throat.
• Avoid tobacco smoke. Active or passive smoking can worsen wheezing.
• Take all prescribed medications. Follow the doctor's instructions.