Cough is a protective reflex of the respiratory system. It occurs as normal physiological process and also sometimes due to disease condition.
Why do we cough?
Cough is intended to expel anything by force of air out of the respiratory tract. Cough is a natural phenomenon and everyone including animals coughs some time or other as part of normal body physiology and protective mechanism.
But this cough can be problematic if it is
a) Very hoarse, exhausting and weakening the body. This can be stressful on the heart.
b) If it is of long standing, leading to disturbance of normal life like sleep and work.
1) Obstructive cough: This is a cough seen when there is an obstruction or material entry into the respiratory tract instead of gut. It is commonly seen when we drink water hastily. If water or food particles drip into the respiratory tract then we cough heavily as the water is tried to be expelled from the tract by reflex activity.
2) Allergic cough: It happens due to allergens or substance which cause allergy to respiratory tract. Ex: Dust, irritating chemicals, pollen from plants etc. This cough can be severe and exhausting with strain on heart especially in children and old age people.
3) Inflammatory cough: This is due to inflammation of respiratory tract whereby there is soreness and redness of mucous layers. This inflammation is irritating to the tissue and hence there arises cough.
4) Infectious cough: This is cough seen in case of severe infection by virus or bacteria. The cases like tuberculosis, cold, chronic obstructive pulmonary disorder (COPD), bronchitis, pneumonia, diphtheria shows this cough symptoms. In fact it is a indicative sign of tuberculosis if cough last for more than 2 weeks especially at night. Here the infection by bacteria or virus leads to inflammatory reactions and also accumulation of phlegm. During these infections the respiratory tract is very sensitive and hence even small allergy leads to hoarse and prolonged coughs. Further the phlegm accumulation is obstructive for normal breathing so tract tries to expel the accumulated phlegm for free respiration. This cough accompanied with phlegm expulsion is termed as ‘wet cough’.
Ex: Whooping cough.
5) Dry cough: This is a not a hoarse cough. Dry cough symptoms are that, it is not from deep, it is from throat itself. Even there is no phlegm expulsion by cough. It is due to allergens or mild inflammations of throat especially.
Reasons for dry cough include mostly irritation to throat or bronchi by smoke, dust, harsh fumes (like chilly powder, organic liquids, acids etc.), inflammation of throat or bronchi by infection/
6) Wet cough: Cough which comes out from lungs as if from deep inside is wet cough. It is intended even to expel phlegm by cough. As mentioned above it is seen during infectious diseases like tuberculosis. Here the phlegm acts as a diagnostic aid. The colour of the phlegm, the microbes in it gives an idea of type of infection and also severity of disease.
Types of cough based on the symptoms
If we notice cough, not all coughing are similar. They vary as
a) Continuous cough: This is a symptom seen especially in old age people with respiratory disorders and also sometimes in youngsters and adults. The cough is continuous and may be problematic such that the person has no time to breath and gasps for air.
The reasons seems to be increased sensitivity of respiratory tract to even normal dust and fumes. This type of chronic cough develops even in those with smoking habit and also in those with cold, flu, COPD etc. Quitting smoking and decrease of infection , inflammation will help reduce this type of cough
b) Cough at night: Cough at night is one of the symptoms of tuberculosis, whooping and few other diseases. Some old people also develop cough at night and the difference is in TB patients cough can be wet type while in other just a dry one. Dry cough can be managed by anti-tussives easily but wet cough need antibiotics and other medicines.
c) Blood in cough: This is due to some blood or clot in the lungs which is expelled while coughing. It has many reasons so check for details in the official link blood in cough.