• When blood is coughed up
• When it is accompanied by chest pain
• When there is difficulty breathing or shortness of breath
• If there is also unintentional weight loss

• Smoking (smoke destroys the cells in the lining of the breathing tubes so that mucus cannot be expelled normally, leading to a chronic cough)
  • Includes exposure to second-hand smoke
• Common cold, influenza, and other viral infections (with yellow or white mucus) are the most common causes
• Drugs (such as ACE inhibitors or expectorants) cause persistent, dry, non-productive coughs
• Stress (if the cough disappears during sleep, then stress may be the cause)
• Allergies
• Aspiration (see foreign object aspiration or ingestion)
• Atelectasis
• Bacterial infection (bronchiectasis, bronchitis, pneumonia, sinusitis or tracheitis)
  • Often with rusty or green mucus
• Viral infection (bronchiolitis, croup, pneumonia, upper respiratory infection)
• Congestive heart failure
• Environmental pollution
• Gastroesophageal reflux
• Postnasal drip
• Asthma
• Diagnostic tests (such as bronchoscopy or pulmonary function tests)
• Medical treatments (such as intermittent positive pressure breathing, or incentive spirometry)
• Lung cancer
• Emphysema

Increasing humidity in the air may help. A vaporizer and a steamy shower are two ways to increase the humidity.

Drink extra fluids to help thin secretions and make them easier to cough up.

Glyceryl guaiacolate (guaifenesin, such as in Robitussin) is available without prescription and may help liquefy the mucus. Drink lots of fluids if taking this medication.

When a cold and a stuffy, runny nose accompany the cough, it is often caused by mucus dripping down the back of the throat. A decongestant that opens the nasal passages will relieve this postnasal drip, and is the best treatment for that type of cough.

Decongestants such as phenylephrine, pseudoephedrine or combinations of these two decongestants are available as over-the-counter cold medications. Don't give decongestants to a child under six years of age unless prescribed by the doctor. It is important to talk to your healthcare provider before using any cough medications for children under two.

If you have high blood pressure (hypertension), consult your doctor before taking decongestants.

Coughs due to chronic postnasal drip are probably caused by either sinus infection or allergy. If allergy is the cause, this is typically treated by avoiding the trigger (allergen) that is causing the allergy. In addition, anti-histamines and a steroid nasal spray are sometimes used to suppress the allergic inflammation.

Dry, tickling coughs can be relieved by sucking on cough lozenges or hard candy. (However, never give a lozenge or hard candy to a child under 3 years old because it is a choking hazard.)

Codeine is a very effective cough suppressant, but has some negative side effects, can lead to physical dependence and addiction and requires a prescription. Dextromethorphan (such as in Vick's Formula 44 of Robitussin DM) is an effective cough suppressant that is available without prescription.

• A violent cough begins suddenly, or there is a high-pitched sound (stridor) when inhaling. (The person might have inhaled a small object.)
• The cough produces blood in any form. This should be treated as an emergency.
• There is a cough in an infant less than 3 months old.
• There is shortness of breath or difficulty breathing.
• Coughing is accompanied by other symptoms such as fever or abdominal swelling.
• A cough is accompanied by unintentional weight loss.
• The cough is producing thick, foul-smelling, rusty or greenish mucus.
• Frequent coughing lasts for more than 10 days.

• Type
  • Are you coughing up blood?
    • Is visible blood coughed up?
    • Is there blood-streaked sputum?
    • Are you coughing up large amounts of blood?
    • Are there repeated episodes of coughing up blood?
  • Do you bring up any mucus/sputum when you cough?
    • Does the sputum contain pus?
    • Does the sputum contain pus and have a foul odor?
    • Does the sputum look like clear, sticky mucus?
    • Is the sputum white and frothy?
    • Is pink, frothy material coughed up?
    • Is the sputum adhesive, thick, hard to cough up?
    • Are you coughing up brownish plugs?
    • How much sputum is produced (about how many cups per day)?
• Quality
  • Is the cough severe?
  • Is the cough dry?
  • Does the cough sound like a seal barking?
• Time pattern
  • Is the cough worse at night?
  • Did it begin suddenly?
  • Has it been increasing recently?
  • How long has the cough lasted (for how many weeks?)
  • Has the cough been chronic and has it changed pattern recently?
  • Do spells of coughing occur repeatedly (recurrent)?
  • Are coughing spells composed of a sequence of separate episodes?
  • Does the cough change?
    • Is it variable over hours?
• Aggravating factors
  • Is the cough worse when you are lying on one side?
  • Is it worse when first arising from sleep?
• Associated complaints
  • Are there sudden periodic attacks of coughing with gagging and vomiting?
• Other
  • What other symptoms are also present?

• Bronchoscopy
• Lung scan
• Pulmonary function tests
• Sputum analysis (if the cough produces sputum)
• X-ray of the chest