Allergic asthma is a common type of asthma. Typical symptoms are recurrent episodes of wheezing, shortness of breath, chest tightness or coughing, which are mostly associated with exposure to allergens, cold air, physical and chemical stimuli, as well as viral upper respiratory tract infections and exercise. Aura symptoms such as nasal congestion, sneezing and itchy eyes often precede the attack. Symptoms may occur within minutes, may last for hours to days, and may resolve on their own with treatment. Symptoms tend to flare up or worsen at night. In severe attacks, severe dyspnea and hypoxemia may occur within a short time. People with fully controlled asthma may have no symptoms. If a patient experiences recurrent attacks of wheezing, shortness of breath, chest tightness or coughing, he or she should seek prompt medical attention and treatment after diagnosis to avoid delays.