Asthma is a chronic condition that occurs when the main air passages of your Lungs, the bronchial tubes, become inflamed. The Muscles of the bronchial walls tighten and extra mucus is produced, causing your airways to narrow. This can lead to everything from minor wheezing to severe difficulty in breathing. Asthma can develop at any age. If you're younger than 30, your asthma is probably triggered by allergies. Many people older than 30 with asthma are also allergic to airborne particles

Respiratory system

Lungs especially the Alveoli and bronchii

The four main classifications of asthma are:

Mild intermittent: This is the mildest form of asthma. When uncontrolled, it causes symptoms up to two days a week and up to two nights a month. Mild persistent: You have this form of asthma if you have symptoms more than two nights a month and more than twice a week, but no more than once in a single day. Moderate persistent: When not controlled, moderate persistent asthma causes symptoms every day and more than one night a week. Severe persistent: This is the most severe form of asthma, causing symptoms throughout the day on most days and frequently at night.

You're more likely to develop asthma if you have an inherited predisposition to the condition and are sensitive to allergens or irritants in your environment. In fact, the inflammation that causes asthma makes your airways overly sensitive to a wide range of environmental triggers. For some people with asthma, particularly older adults, Respiratory allergies don't seem to play a role. Instead, exposure to any irritant such as a virus, cigarette smoke, Cold air, and even emotional stress can trigger wheezing. In most cases though, asthma results from a combination of allergic and no allergic responses. You may react to one or more of the following triggers:

Allergens, such as pollen, cockroaches and molds. Air pollutants and irritants. Smoking and secondhand smoke. Respiratory infections, including the common Cold. Physical exertion, including exercise. Cold air. Certain medications, including beta-blockers, aspirin and other nonsteroidal anti-inflammatory drugs. Sulfites preservatives added to some perishable foods. Gastroesophageal reflux disease (GERD), a condition in which Stomach acids back up into your esophagus. GERD may trigger an asthma attack or make an attack worse. Sinusitis

Risk Factors

In fact, asthma is the most common chronic illness of childhood. Among young children, asthma is more common in boys than in girls. But after puberty asthma becomes more common in girls. Researchers have identified a number of factors that may increase your chances of developing asthma. These include:

Living in a large urban area, especially the inner city, which may increase exposure to many environmental pollutants Exposure to secondhand smoke Exposure to occupational triggers, such as chemicals used in farming and hairdressing, and in paint, steel, plastics, and electronics manufacturing Having one or both parents with asthma Respiratory infections in childhood Low birth weight Obesity Gastroesophageal reflux disease (GERD)

Asthma signs and symptoms can range from mild to severe. In some cases, your breathing may be so laboured that an asthma attack becomes life threatening. All asthma attacks give a warning. Learning to recognize warning signs and treating symptoms early can help prevent attacks or keep them from becoming worse.

Warning signs and symptoms for adults can include:

Increased shortness of breath or wheezing Disturbed sleep caused by shortness of breath, coughing or wheezing Chest tightness or pain Increased need to use bronchodilators medications that open up airways by relaxing the surrounding Muscles A fall in peak flow rates as measured by a peak flow meter, a simple and inexpensive device that allows you to monitor your own lung function

Warning signs and symptoms for children can include:

An audible whistling or wheezing when your child exhales Coughing, especially if the Cough is frequent and occurs in spasms Waking at night with coughing or wheezing Shortness of breath, which may or may not occur when your child exercises A tight feeling in your child's Chest

Diagnosing asthma can be difficult. Signs and symptoms can range from mild to very severe and are often similar to those of other conditions, including emphysema, early congestive Heart failure or vocal cord dysfunction. In most cases you'll be asked to give a complete medical history and have a physical exam. You may also be given lung (pulmonary) function tests to determine how much air moves in and out as you breathe. The two most common tools to measure lung function are spirometers and peak flow meters (Lung function tests are usually done before and after taking a medication known as a bronchodilator to open your airways. If your lung function improves with use of a bronchodilator, it's likely you have asthma) Methacholine bronchial challenge (If you have asthma, inhaling a known asthma trigger called methacholine will cause mild constriction of your airways, which can be measured with a lung function test).

The best way to prevent asthma attacks is to identify and avoid indoor and outdoor allergens and irritants. You can do several things on your own to maintain overall health and lessen the possibility of attacks:

Exercise: You don't have to be sedentary if you have asthma. Regular exercise can strengthen your Heart and Lungs so that they don't have to work so hard. Aim for 30 minutes of exercise on most days. If you've been inactive, start slowly and try to gradually increase your activity over time. Keep in mind that Cold-weather exercises, such as skiing, are more likely to cause wheezing. If you do exercise in Cold weather, wear a facemask to warm the air you breathe. And don't exercise if the temperature is below zero. Activities such as golf, walking and swimming are less likely to trigger attacks, but be sure to discuss any exercise program with your doctor. Use your air conditioner: This helps reduce your exposure to airborne pollen from trees, grasses and weeds. Air conditioning also lowers indoor humidity and can reduce your exposure to dust mites. If you don't have air conditioning, try to keep your windows closed during pollen season. Decontaminate your decor: Minimize dust that may aggravate nighttime symptoms with an easy room makeover. Maintain optimal humidity: Keep humidity low in your home and office. If you live in a damp climate, talk to your doctor about using a dehumidifier. Keep indoor air clean: Have a utility company check your air conditioner and furnace once a year. Change the filters in your furnace and air conditioner according to the manufacturer's instructions. Also consider installing a small-particle filter in your ventilation system. If you use a humidifier, change the water daily. Reduce pet dander: If you're allergic to dander, avoid pets with fur or feathers. Having pets regularly bathed or groomed also may reduce the amount of dander in your surroundings. Clean regularly: Clean your home at least once a week. Because cleaning stirs up dust, however, wear a mask or, if you can, have someone else clean. Limit use of contact lenses: Lenses when the pollen count is high. Pollen grains can try substituting eyeglasses for your contact becomes trapped under the lenses.

In addition to knowing and avoiding your triggers, adopt the following behaviours:

Develop an action plan: With your doctor and health care team, write a detailed plan for taking maintenance medications and managing an acute attack. Then be sure to follow your plan. Asthma is an ongoing condition that needs regular monitoring and treatment. Taking control of your treatment can make you feel more in control of your life in general. Monitor your breathing: Like many people, you may recognize your own signs of an impending attack, such as slight coughing, wheezing or shortness of breath. But because your lung function may decrease before you notice any signs or symptoms, regularly measure your peak airflow with a home peak flow meter. Treat attacks early: If you act quickly, you're less likely to have a severe attack. You also won't need as much medication to control your symptoms. When your peak flow measurements decrease and alert you to an impending attack, take your medication as instructed and immediately stops any activity that may have triggered the attack. If your symptoms don't improve, get medical help as directed in your action.

A number of individual medications exist for asthma, and many are used in combination with others. Your doctor can help you decide which option is best for you based on your age and the severity of your symptoms. In general, the four types of treatments are:

Long-Term-Control Medications.

These medications are taken daily, usually on a long-term basis, to achieve and maintain control of persistent asthma.

Inhaled corticosteroids fluticasone (Flovent), budesonide (Pulmicort), triamcinolone (Azmacort), flunisolide (Aerobid) and beclomethasone (Qvar). Advair Diskus is a combination inhaler containing fluticasone and salmeterol Long-acting beta-2 agonists. These medications are part of a group of medications called bronchodilators. Leukotriene modifiers Theophylline (Uniphyl). You take this bronchodilator in pill form every day. It's especially helpful for relieving your nighttime symptoms of asthma. Cromolyn and nedocromil

Quick-Relief Medications

You use these as needed for rapid, short-term relief of symptoms during an attack.

Short-acting beta-2 agonists These bronchodilators begin working within minutes and last four to six hours. But Ipratropium (Atrovent). Your doctor might occasionally prescribe this anticholinergic for the immediate relief of your asthma symptoms. Oral and intravenous corticosteroids including prednisone, methylprednisolone, hydrocortisone and others

Other Treatments Immunotherapy Or Allergy Desensitization Shots

These decrease your body's sensitivity to a particular allergen. If you have allergic asthma that can't be easily controlled by avoiding triggers and using medication, Allergy desensitization shots (immunotherapy) may help you

Anti-Ige Monoclonal Antibodies

These are designed to prevent your immune system from reacting to allergens. If you have allergies, your immune system produces Allergy-causing IgE antibodies to attack substances that generally cause no harm, such as pollen, dust mites and pet dander. Omalizumab (Xolair) can reduce the number of asthma attacks you experience by blocking the action of these antibodies.

Asthma accounts for millions of missed school days and workdays annually. It's also a frequent reason for emergency room visits and hospitalizations. Controlling your asthma can also help you avoid the serious side effects that may accompany long-term use of oral and intravenous corticosteroids, which are sometimes used to stabilize severe asthma attacks. Using inhaled corticosteroids, which have fewer side effects, can help you reduce the need for other forms of these drugs.