A cough is a spontaneous reflex that helps clear dust, germs, and mucus out of the throat and airways. Coughing keeps the body safe from invaders, and most coughs are not serious

Colds, sinus congestion or infection, and allergies can cause a cough, as can the flu. In some cases, a cough can be a symptom of a more serious condition like pneumonia or gastroesophageal reflux disease (GERD). Some medicines—including those that treat kidney or heart disease or high blood pressure—lung disease, smoking, and allergies can also cause a cough.

This article covers the symptoms, types, and causes of a cough; diagnosis and treatment of a cough; and when to get help for a cough.

Mom coughing and feeling sick

Causes of a Cough
A cough can be categorized as acute (short-term) or chronic (long-term).

The most common causes of acute cough are:

• Cold, flu, or acute bronchitis (also known as a chest cold)
• Allergy or hay fever
• A flareup of asthma or chronic obstructive pulmonary disease (COPD), a lung disease that makes breathing difficult
• Dust or smoke
• Upper respiratory infection (URI)

Some causes of chronic cough include:

• Chronic bronchitis
• Asthma
• Allergies
• Smoking
• Chronic obstructive pulmonary disease (COPD)
• Postnasal drip (when mucus from the nose reaches the back of the throat)
• Medications, including some that treat heart disease and high blood pressure
• Tuberculosis

What Medications Can Cause a Cough?
Medications known for causing a cough include:

ACE inhibitors: ACE (angiotensin-converting enzyme) inhibitors are medicines that lower blood pressure. They are also prescribed for heart disease, kidney disease, and diabetes. People on ACE inhibitors could experience dry cough as a side effect.
Opioids: Opioids are pain relievers prescribed for surgery, major injury, or chronic pain. About 30% to 66% of people who take prescription opioids could experience chronic cough.
Statins: Statins lower cholesterol, and coughing is a well-known side effect.
There are rare reports of coughing as a side effect of:

• Omeprazole, a medication for acid reflux disease
• Arava (leflunomide, an arthritis treatment
• Interferon (IFN) and ribavirin (under brand names Rebetol and Virazole), which are medications for Hepatitis C
• Januvia (sitagliptin), a type 2 diabetes treatment

How to Treat a Cough
Short-term coughs usually go away on their own, but there are ways to manage them. To treat a cough, it might help to do the following:

• Drink plenty of fluids
• Rest
• Add lemon and honey to a warm beverage
• Avoid carbonated drinks
• Ingest a mixture of lemon and honey
• Sit in a steamy bathroom or run a humidifier (for dry cough)
• Take over-the-counter painkillers like Advil and Motrin (ibuprofen)
• Take over-the-counter cough medicines or cough drops
• Avoid allergens and smoke
• Stop smoking

Chronic, long-term coughs require medical attention, and treatments might include:

• A bronchodilator or steroid inhaler for asthma
• Antihistamines for allergies
• Antibiotics if the cough is a result of a bacterial infection like pneumonia
• Antacids or proton pump inhibitors (PPI) for GERD
• Bronchodilators for COPD

Types of Cough
The two main types of cough are:

• Acute (short-term) cough: An acute cough lasts up to three weeks and does not require medical attention, unless there are other symptoms, like chest pain, shortness of breath, fever, drowsiness, or headache.
• Chronic (persistent or long-term) cough: These coughs last longer than three weeks and can be a sign of a chronic condition, including asthma and allergy, or more serious conditions like lung disease.

There are different kinds of acute and chronic coughs, including:

• Productive cough: A cough with phlegm or mucus
• Dry (unproductive) cough: A cough without mucus

Complications and Risk Factors Associated With a Cough
In some cases, a cough could mean a life-threatening condition, such as:

• Pulmonary embolism: When a blood clot travels to the lungs. Symptoms include a dry cough with shortness of breath.
• Collapsed lung: When the lung is deflated. Symptoms include chest pain, shortness of breath, and dry cough.
• Heart failure: Symptoms of heart failure can include swelling in the legs (edema), shortness of breath, and cough.

Tests to Diagnose the Cause of a Cough
To determine the cause of a cough, a healthcare provider might ask about other symptoms like:

• Fever
• Chest pain
• Shortness of breath
• Coughing up blood
• Headaches
• Drowsiness
• Confusion

A medical professional might also ask questions about the cough’s history and the patient’s medical history. This might include inquiring about:

• Mucus color
• Allergies
• Medical conditions
• Medications
• Smoking

One or more of the following medical tests could pinpoint the reason behind a cough:

• Blood tests to diagnose infections like pneumonia
• Mucus (sputum) tests for a bacterial infection or lung cancer
• Chest X-ray
• CT scan, which can capture images of the heart, lungs, and other organs
• Spirometry, which measures lung function
• Methacholine challenge tests, which measure lung reactions and help with diagnosing asthma

When to See a Healthcare Provider
When a cough lasts longer than three weeks or is accompanied by the following symptoms, it is advised to see a healthcare provider as soon as possible:

• Shortness of breath
• Coughing up blood
• Spasms
• Turning blue
• For children, a fever for longer than two days
• Lumps in the throat

Summary
A cough is a spontaneous reflex that keeps the body safe from dust, bacteria, and other pathogens. The most common reasons behind an acute cough include the common cold, flu, allergies, dust or smoke, or a flare-up of a chronic condition like asthma. Medications that can cause a cough include ACE inhibitors, which reduce blood pressure and are prescribed for heart and kidney disease.

See a healthcare provider immediately if you’re experiencing shortness of breath, a bloody cough, spasms, lumps in the throat, or turning blue with a cough.