Can't Stop Coughing? It May Be Chronic Cough!

Chron­ic cough is usu­al­ly defined as a cough that lasts for three weeks or longer. It is a very com­mon prob­lem and is the fifth most com­mon symp­tom for which out­pa­tient care is sought.

Although chron­ic cough is usu­al­ly not seri­ous, it can be asso­ci­at­ed with a vari­ety of unpleas­ant effects, includ­ing phys­i­cal exhaus­tion, self-con­scious­ness, insom­nia, headache, dizzi­ness, mus­cle strain, hoarse­ness, exces­sive per­spi­ra­tion, and leak­age of urine dur­ing cough­ing. In addi­tion, the patien­t’s mood may be dis­turbed because of an under­ly­ing wor­ry that some­thing is wrong.”

In almost all cas­es, an under­ly­ing cause for chron­ic cough can be found and treated.

Caus­es

The most com­mon caus­es of chron­ic cough are post­nasal drip, asth­ma, and gas­troe­sophageal reflux dis­ease (GERD). These three caus­es are respon­si­ble for up to 90 per­cent of all cas­es of chron­ic cough. Less com­mon caus­es include infec­tions, med­ica­tions, and chron­ic lung diseases.

Post­nasal Drip

Post­nasal drip is the most com­mon cause of chron­ic cough. Post­nasal drip is a con­di­tion that devel­ops when secre­tions from the nose chron­i­cal­ly drip into the back of the throat. These secre­tions can cause throat inflam­ma­tion and trig­ger a cough.

Under­ly­ing caus­es of post­nasal drip include aller­gies, colds, and sinusi­tis. In addi­tion, some peo­ple have chron­ic inflam­ma­tion of the nasal pas­sages and run­ny nose, which can also cause post­nasal drip.

Peo­ple with post­nasal drip may com­plain of symp­toms includ­ing stuffy or run­ny nose, sen­sa­tion of liq­uid in the back of the throat, or fre­quent throat clear­ing. Some peo­ple may have so-called silent” post­nasal drip; they have post­nasal drip but don’t real­ize it. The physi­cian will some­times sus­pect post­nasal drip based on the appear­ance of the patien­t’s throat. The physi­cian will always con­sid­er, and some­times treat, post­nasal drip in a patient with chron­ic cough when no oth­er appar­ent cause is present.

Asth­ma

Asth­ma is gen­er­al­ly report­ed to be the sec­ond most fre­quent cause of chron­ic cough in adults and is the lead­ing cause in chil­dren. A cough caused by asth­ma is often accom­pa­nied by wheez­ing and short­ness of breath; how­ev­er, some peo­ple have a con­di­tion, known as cough vari­ant asth­ma, in which cough is the only symp­tom of asthma.

A diag­no­sis of asth­ma as the cause of the cough is also sus­pect­ed when the patient has a his­to­ry of mul­ti­ple aller­gies, or has a fam­i­ly his­to­ry of asth­ma. Asth­ma relat­ed cough may be sea­son­al, may fol­low an upper res­pi­ra­to­ry infec­tion, or may get worse on expo­sure to cold, dry air, or cer­tain fumes or fragrances.

Gas­troe­sophageal Reflux Disease

Gas­troe­sophageal reflux dis­ease, or GERD, is a dis­ease in which acid from the stom­ach flows back (reflux­es) into the tube con­nect­ing the stom­ach and the throat (the esoph­a­gus). The pres­ence of this acidic mate­r­i­al in the esoph­a­gus and/​or its sub­se­quent pres­ence in the throat or even the lungs, can lead to chron­ic irri­ta­tion and cough­ing. (See the gas­troe­sophageal reflux dis­ease” brochure).

GERD is believed to be the third most com­mon cause of chron­ic cough. Many patients with cough due to GERD com­plain of symp­toms includ­ing heart­burn or a sour taste in the mouth; how­ev­er, these symp­toms are absent in more than 40 per­cent of patients with cough due to reflux.

Diag­no­sis

The doc­tor will ask the patient for a care­ful, detailed descrip­tion of the his­to­ry of the cough and of any oth­er symp­toms that may be present. In par­tic­u­lar, the doc­tor will be inter­est­ed in symp­toms sug­gest­ing post­nasal drip, asth­ma, or GERD. Tak­en togeth­er, these three con­di­tions account for 90 per­cent of cas­es of chron­ic cough. In one study, these con­di­tions were respon­si­ble for 99.4 per­cent of cas­es of cough in patients who were non­smok­ers, did not take ACE inhibitors and had nor­mal (or near nor­mal) and sta­ble chest x‑rays.

In most cas­es, the his­to­ry and the patien­t’s response to treat­ment (see below) give the doc­tor enough infor­ma­tion to deter­mine the prob­a­ble cause of the cough. The doc­tor may wish to obtain a chest x‑ray as part of the ini­tial evaluation.

If asth­ma is sus­pect­ed but can­not be con­firmed, the doc­tor may per­form lung func­tion tests. These allow the doc­tor to study the pat­tern of air­flow into and out of the lungs. A test called a metha­choline chal­lenge may also be used to help diag­nose asth­ma. In this test, lung func­tion is mea­sured before and after a patient inhales a med­i­cine called metha­choline. A patient with asth­ma will have a decrease in lung func­tion after inhal­ing this med­i­cine. The effect of this med­i­cine is short-lived, eas­i­ly reversed with addi­tion­al med­ica­tion and gen­er­al­ly not notice­able to the patient. It is a safe and com­mon­ly used test.

If the doc­tor needs addi­tion­al infor­ma­tion to con­firm a diag­no­sis of GERD, a test may be ordered in which the acid­i­ty of the flu­id in the esoph­a­gus is mea­sured using a small probe that the patient swal­lows. Pro­longed peri­ods of high acid­i­ty sug­gest the pres­ence of GERD.

If lung dis­ease, such as bronchiec­ta­sis or lung can­cer, is sus­pect­ed, addi­tion­al tests and a refer­ral to a lung spe­cial­ist may be required.

Treat­ment

Treat­ment of chron­ic cough should be direct­ed at the under­ly­ing cause. Treat­ment of the most com­mon caus­es of chron­ic cough is dis­cussed here. Patients with lung dis­ease or less com­mon caus­es of cough may be treat­ed differently.

Treat­ment of post­nasal drip

Patients with or with­out symp­toms of post­nasal drip may be treat­ed for this con­di­tion to see if the cough improves. Ther­a­py may include anti­his­t­a­mines and decon­ges­tants, nasal steroids, or ipra­t­ropi­um nasal spray. If sinusi­tis is sus­pect­ed as the cause of the post­nasal drip, antibi­otics may be helpful.

Treat­ment of cough vari­ant asthma

Patients whose cough is due to asth­ma will receive stan­dard treat­ment for asth­ma, which includes inhaled bron­chodila­tors and inhaled steroids. These inhaled med­i­cines act to decrease inflam­ma­tion (swelling) of the air­ways. In some cas­es, oral steroids are giv­en for a lim­it­ed peri­od of time. (See the man­ag­ing asth­ma” brochure).

Treat­ment of gas­troe­sophageal reflux

Cough due to GERD usu­al­ly responds to a reg­i­men that includes one or more of the following:

  • Avoid­ing intake of sub­stances that increase reflux, such as foods with high fat con­tent, choco­late, and exces­sive alcohol.
  • Stop smok­ing
  • Eat­ing three meals a day with­out snacking.
  • Avoid­ing meals for two to three hours before lying down.
  • Ele­vat­ing the head of the bed while sleeping.
  • Tak­ing med­ica­tion to decrease acid­i­ty in the stomach.
  • These mea­sures are usu­al­ly effec­tive in some­one with con­firmed GERD, but the time it takes for patients to see improve­ment in cough can be as long as six months. (See the gas­troe­sophageal reflux dis­ease” brochure).

Your doc­tor is the best resource for find­ing out impor­tant infor­ma­tion relat­ed to your par­tic­u­lar case. Not all patients with chron­ic cough are alike and it is impor­tant that your sit­u­a­tion is eval­u­at­ed by some­one who knows you and your his­to­ry well.

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