Cough Symptoms, Causes and Risk Factors
Coughing is seen in many medical conditions. It is important to take note of the duration, type and features of your cough as well as any other symptoms that come with your cough. This information will be very helpful to your healthcare provider when looking for the cause of your cough and the most appropriate treatment.
Coughing is a symptom. We can classify a cough by its duration (how long it lasts) and by other specific features:
- Acute cough: Sudden onset and lasts up to 3 weeks.
- Sub-acute cough: Lasts between 3-8 weeks.
- Chronic cough: Lasts for more than 8 weeks.
- Productive cough: Cough than brings up phlegm.
- Dry cough: Cough that does not bring up phlegm.
- Nocturnal cough: Cough that only happens at night.
- Hemoptysis: Coughing blood.
A cough can be the only sign of an illness or it can occur with symptoms of certain diseases of the lung, heart, stomach and nervous system. Some of the symptoms that commonly occur with a cough are:
- Shortness of breath
- Decrease in exercise tolerance (easy fatigability)
- Wheezing or a whistling breathing
- Runny nose
- Sore throat
- Weight loss
- Fever and chills
- Night sweats
- Difficulty swallowing or coughing when swallowing
These are common causes of acute, or short-term cough:
- Upper respiratory tract infections (or URTIs): This is the most common cause of acute cough. URTIs are infections of the throat and are almost always caused by viruses. They are usually associated with fevers, sore throat and runny nose. This group includes the common cold, viral laryngitis and influenza. Whooping cough is a highly contagious respiratory infection that produces a cough that makes a high-pitched “whoop” sound.
- Hay fever (or allergic rhinitis): This common allergic condition can mimic the symptoms of a common cold. It is usually associated with dry cough, sneezing and runny nose. There is usually an allergy trigger in the environment.
- Inhalation of irritants: Acute exposure to some fumes and vapors can cause inflammation of the throat and airway and cause cough.
- Lower respiratory tract infections (or LRTIs): These are infections of the airways below the throat that usually cause cough and fevers. They can affect the airways (bronchitis) or go further into the lungs (pneumonia).
- Lung clot (or pulmonary embolism): This is a potentially life-threatening condition where blood clots travel, usually from leg veins, to the lungs causing sudden shortness of breath and sometimes coughing.
- Lung collapse (or pneumothorax): This is caused by the deflation of the lung. It can be spontaneous or due to chest trauma. More commonly seen in smokers with history of emphysema (air pockets within the lungs), signs of lung collapse include sudden chest pain, dry cough and shortness of breath.
- Heart failure (or pulmonary edema): A weak heart can cause built up of fluid in the lung, causing cough and worsening shortness of breath.
- Post-nasal drip (or upper airway cough syndrome): This condition shows up as dry cough caused by the chronic dripping of mucus from the back of the nose to the throat. Usually this occurs after a recent infection or continuous exposure to an allergy trigger.
- Gastro-esophageal reflux (or GERD): This is also commonly known as acid reflux disease. The acid within the stomach backs its way up to the esophagus. It can potentially leak into the throat causing irritation and dry cough. It is usually associated with heartburn.
Some causes of chronic cough include:
- COPD: The airway and lungs are inflamed, which causes chronic cough with phlegm and shortness of breath.
- Asthma: Asthma can cause sporadic dry cough. This could be a sign that your asthma is not fully controlled. Sometimes cough only happens in specific locations such as the workplace or school.
- Medications: ACE inhibitors (medications for elevated blood pressure), can cause dry cough.
- Chronic lung infections: Some lung infections can cause chronic cough. Tuberculosis, a highly contagious lung infection, can cause fevers, night sweats and cough, sometimes with blood).
- Lung cancer: Cancer originating in the lung or spread from other organs can cause cough, sometimes with blood.
Risk factors for developing a chronic cough are:
- Smoking: Current or former smoking is a major risk factor for chronic cough. This is caused by direct inhalation of cigarette toxins or secondhand smoking (breathing cigarette toxins in the air).
- Allergies: People with allergies have an increased risk of developing cough when exposed to a specific allergy trigger.
- Environmental: Some workplaces may have irritants in the air that one can breathe in and cause cough. High pollution areas or using coal for cooking or heating can also increase your risk of cough.
- Chronic lung diseases: People with asthma, bronchiectasis (enlarged airways), COPD, and previous lung infections with scars are at increased risk of developing cough.
- Female gender: Women have a more sensitive cough reflex, increasing their risk of developing chronic cough.
When to See Your Doctor
See your healthcare provider if you have a cough that won't go away.
Call 911 immediately if you have sudden onset of cough associated with:
- Severe difficulty breathing
- Swollen face and hives
- Severe chest pain
- Coughing blood
Call your doctor if you have developed a cough and:
- Have recently been exposed to a patient with tuberculosis or whooping cough
- Have shortness of breath
- Have fever
- Have bloody mucus with pus
- Have new wheezing or wheezing that doesn't go away with inhalers
- Have worsening leg swelling and shortness of breath, especially when lying flat.
Approved by Scientific and Medical Editorial Review Panel. Last reviewed July 13, 2016.