KARACHI - Experts on Sunday said that the disease of asthma had turned into an alarming condition as about 10 per cent of children in Pakistan were suffering from this disorder, while 5 to 10 per cent of the adult population in the country was suffering from this condition. A research, done by the Aga Khan University (AKU), reveals that the prevalence of asthma in Pakistan has increased to 18 per cent in children of 13-14 age groups, said a leading consultant of the AKUH, Prof Dr Jawed A Khan, while talking to The Nation on the eve of World Asthma Day to be held on May 6. The day in 2008 is being observed with the theme "You Can Control Your Asthma." He said that the epidemiological studies from other parts of the world had also confirmed that asthma prevalence was increasing in the world especially in the developing countries. According to a study, conducted two years back, more than 300 million people in the world are suffering from this disorder, while thousands of people die of the disease every year, he said. He said is a chronic disease of lungs characterised by recurrent breathing problems. The common symptoms of asthma include breathlessness, wheezing, chest tightness, and coughing. During normal breathing, air flows freely in and out of the lungs. However, in a patient with asthma, the airways of the lungs become thick, swollen and inflamed. The airways of asthma patients were very sensitive to environmental changes. Asthma symptoms vary from time to time. Some patients get symptoms very occasionally, once or twice a year, during the change of weather. In spite of extensive research in this field, the causes of asthma increase remain unclear, in fact the rapid increase in asthma prevalence around the world is considered as one of the biggest mystery in modern medicine. There are several possible explanations for the increase in asthma cases. These include changes in lifestyle e.g. increased use of carpets, changes in the dietary pattern in particular, decreased use of fruits and vegetables and increased consumption of fast-food. Increased prevalence of smoking is also being considered as an important factor for the rise in asthma cases in many developing countries. Factors that can set off an asthma attack include inhaled allergens (such as dust mites, pollen, and cat and dog allergens), tobacco smoke, air pollution, exercise, strong emotional expressions (such as crying or laughing), chemical irritants, and certain drugs (aspirin and beta-blockers). Some colouring agents and food preservatives can also cause asthma attack. Flu and common cold are by far the most common reason for worsening of asthma symptoms. Avoidance of allergens and irritants is necessary in order to avoid asthma symptoms. Each person with asthma reacts to a different set of factors and identification of these factors and how to avoid them is a major step for each individual in learning how to control their disease. Allergen avoidance may not always be possible because most patients do not know to which agent they are allergic to; however, skin tests are helpful in this respect. House dust mite, a microscopic insect like creature, is the biggest enemy of asthma sufferer. It thrives in humid and warm conditions and its diets consist of shed scales from the human skin. At home, its sources are bedroom mattress, pillows and carpets, which provide the best warm condition, humidity and food. It is also present in blankets, curtains and furniture. Certain measures can reduce the exposure to house dust mite. This include, removal of carpets, at least from the bedrooms, discarding feathers pillow and using hypoallergenic polyester pillow, encasing the bed with a plastic cover, washing bed-clothes weekly, putting linen and blanket in the sun light at least once a week.