Asthma is a chronic respiratory disorder affecting the airways of the lungs. Asthma is characterized by two important features- airway hyperreponsiveness and bronchoconstriction.
In people with asthma the airways tend to respond in a hyperactive manner to certain stimuli which normally would not trigger any responses in others. This is termed as airway hyperreponsiveness. Bronchoconstriction refers to the narrowing of the airways thereby causing obstruction to the airflow.
Symptoms of Asthma
People with asthma have very sensitive airways. These people respond to asthma triggers by causing the airways to narrow. The narrowing of the airways is caused by inflammation and swelling of the airway lining, the tightening of the airway muscles, and the production of excess mucus. As a result there is obstruction to the airflow in and out of the lungs. This leads to the classic asthma symptoms of respiratory wheezing and difficulty in breathing. Respiratory wheezing is a high-pitched whistling sound, which is usually heard on expiration. Another important characteristic symptom of asthma is dyspnea or difficulty in breathing. Some people with asthma can also complain of chest tightness. This occurs as a result of tightening of the airway muscles, so the person suffering from an asthmatic attack has to put in more effort than normal in order to breathe properly. One of the associated symptoms of asthma is cough. Cough may be caused due to the stimulation of the airways by the asthma trigger factors. An asthmatic attack varies from person to person. It can be mild, moderate or severe.
Types of Asthma
There are different types of asthma. Some of the common types are mentioned below:
This is one of the most common types of asthma. It is induced by a number of allergic factors. Some of the common allergies include allergy to dust, cold weather, eggs, soy, milk and milk products, smoke and pollen. Allergic asthma may also be associated with skin diseases which are triggered by allergies. It is common in childhood. Identifying trigger factors and avoiding them is important to prevent an asthmatic attack.
Exercise induced asthma
This type of asthma is triggered by exercise or any physical exertion. In people, suffering from asthma, their symptoms may be aggravated by exercise. Many people who are not asthmatics may develop the symptoms of asthma after vigorous physical exercise.
This type of asthma is brought on by trigger factors in the workplace. Some common jobs that are associated with occupational asthma include animal breeders, farmers, hairdressers, nurses, painters, and woodworkers. The people who work in these places constantly come in contact with allergens or asthmatic trigger factors and suffer from asthma.
Nocturnal asthma is mainly triggered at night. This is also one of the most common types of asthma. The symptoms of asthma like difficulty in breathing, wheezing in the chest and coughing become worse at night. Often the person suffering from asthma has to rock gently or sit in the chair for hours together as his symptoms become worse after lying down on bed.