Cough

A cough (About this sound pronunciation (help·info) Latin: tussis) is a sudden and often repetitively occurring reflex which helps to clear the large breathing passages from secretions, irritants, foreign particles and microbes. The cough reflex consists of three phases: an inhalation, a forced exhalation against a closed glottis, and a violent release of air from the lungs following opening of the glottis, usually accompanied by a distinctive sound. Coughing can happen voluntarily as well as involuntarily.
Treatment :
Treatment should target the cause; for example, smoking cessation or discontinuing ACE inhibitors. Some people may be worried about serious illnesses, and reassurance may suffice. Cough suppressants such as codeine or dextromethorphan are frequently prescribed, but have been demonstrated to have little effect. Other treatment options may target airway inflammation or may promote mucus expectoration. As it is a natural protective reflex, suppressing the cough reflex might have deleterious effects, especially if the cough is productive.
Classification:
A cough can be classified by its duration, character, quality, and timing. The duration can be either acute (of sudden onset) if it is present less than three weeks, subacute if it is present between three and eight weeks, and chronic when lasting longer than eight weeks. A cough can be dry or productive, depending on whether sputum is coughed up. It may occur only at night (then called nocturnal cough), during both night and day, or just during the day.
Differential diagnosis:
A cough in children may be either a normal physiological reflex or due to an underlying cause. In healthy children it may be normal in the absence of any disease to cough ten times a day. The most common cause of an acute or subacute cough is a viral respiratory tract infection.In adults with a chronic cough, i.e. a cough longer than 8 weeks, more than 90% of cases are due to post-nasal drip, asthma, eosinophilic bronchitis, and gastroesophageal reflux disease.The causes of chronic cough are similar in children with the addition of bacterial bronchitis.
Infections:
A cough can be the result of a respiratory tract infection such as the common cold, pneumonia, pertussis, or tuberculosis. In the vast majority of cases, acute coughs, i.e. coughs shorter than 3 weeks, are due to the common cold. In people with a normal chest X-ray, tuberculosis is a rare finding. Pertussis is increasingly being recognised as a cause of troublesome coughing in adults.
Gastroesophageal reflux:
In people with unexplained cough gastroesophageal reflux disease should be considered. This occurs when acidic contents of the stomach come back up into the esophagus. Symptoms usually associated with GERD include heartburn, sour taste in the mouth, or a feeling of acid reflux in the chest, although, more than half of the people with cough from GERD don’t have any other symptoms. An esophageal pH monitor can confirm the diagnosis of GERD. Sometimes GERD can complicate another respiratory process like asthma or bronchitis. The treatment involves anti-acid medications and lifestyle changes with surgery indicated in cases not manageable with conservative measures.
Air pollution:
Coughing may be caused by air pollution including tobacco smoke, particulate matter, irritant gases, and dampness in the home. The human health effects of poor air quality are far reaching, but principally affect the body's respiratory system and the cardiovascular system. Individual reactions to air pollutants depend on the type of pollutant a person is exposed to, the degree of exposure, the individual's health status and genetics. People who exercise outdoors, for example, on hot, smoggy days increase their exposure to pollutants in the air. Foreign body:
A foreign body can sometimes be suspected, for example if the cough started suddenly when the patient was eating. Rarely, sutures left behind inside the airway branches can cause coughing. A cough can be triggered by dryness from mouth breathing or recurrent aspiration of food into the windpipe in people with swallowing difficulties.
ACE inhibitor:
Angiotensin-converting enzyme inhibitors are drugs used in diabetics, heart disease, and high blood pressure. In 25-10% of the people who take it, it can cause them to have a cough as a side effect. Stopping the drug is the only way to make the cough go away. Such medicines for hypertension are very common in use such as ramipril and quinapril. There are cases of "cough of unknown origin" who had resolution with stopping the drug.
Psychogenic cough:
A psychogenic cough ("habit cough" or "tic cough") may be the cause in the absence of a physical problem. In these instances emotional and psychological problems are suspected. However, other illnesses have to be ruled out before a firm diagnosis of psychogenic cough is made. Psychogenic cough is thought to be more common in children than in adults. A possible scenario: psychogenic cough develops in a child who has a chronically ill brother or sister.
Pathophysiology:
A cough is a protective reflex in healthy individuals which is influenced by psychological factors. The cough reflex is initiated by stimulation of two different classes of afferent nerves, namely the myelinated rapidly adapting receptors, and nonmyelinated C-fibers with endings in the lungs. However it is not certain that the stimulation of nonmyelinated C-fibers leads to cough with a reflex as it's meant in physiology (with its own five components): this stimulation may cause mast cells degranulation (through an asso-assonic reflex) and edema which may work as a stimulus for rapidly adapting receptors.
Diagnostic approach:
he determination of the cause of a cough usually begins by determining if it is specific or nonspecific in nature. A specific cough is one associated with other symptoms and further workup is dependent on these symptoms while a non specific cough occurs without other signs and symptoms. Further workup may include labs, x rays, and spirometry.
Treatment:
The treatment of a cough in children is based on the underlying cause with the use of cough medicine supported by little evidence and thus not recommended by the American Academy of Pediatrics.A trial of antibiotics or inhaled corticosteroids may be tried in children with a chronic cough in an attempt to treat protracted bacterial bronchitis or asthma respectively.
Complications:
The complications of coughing can be classified as either acute or chronic. Acute complications include cough syncope (fainting spells due to decreased blood flow to the brain when coughs are prolonged and forceful), insomnia, cough-induced vomiting, rupture of blebs causing spontaneous pneumothorax (although this still remains to be proven), subconjunctival hemorrhage or "red eye", coughing defecation and in women with a prolapsed uterus, cough urination. Chronic complications are common and include abdominal or pelvic hernias, fatigue fractures of lower ribs and costochondritis.
Epidemiology:
A cough is the most common reason for visiting a primary care physician in the United States.