Question: how is asthma diagnosed

Reference:
 Asthma Overview Asthma is a condition in which your airways narrow and swell and produce extra mucus. This can make breathing difficult and trigger coughing, wheezing and shortness of breath. For some people, asthma is a minor nuisance. For others, it can be a major problem that interferes with daily activities and may lead to a life-threatening asthma attack. Asthma can't be cured, but its symptoms can be controlled. Because asthma often changes over time, it's important that you work with your doctor to track your signs and symptoms and adjust treatment as needed. Symptoms Asthma symptoms vary from person to person. You may have infrequent asthma attacks, have symptoms only at certain times - such as when exercising - or have symptoms all the time. Asthma signs and symptoms include: - Shortness of breath - Chest tightness or pain - Trouble sleeping caused by shortness of breath, coughing or wheezing - A whistling or wheezing sound when exhaling (wheezing is a common sign of asthma in children) - Coughing or wheezing attacks that are worsened by a respiratory virus, such as a cold or the flu Signs that your asthma is probably worsening include: - Asthma signs and symptoms that are more frequent and bothersome - Increasing difficulty breathing (measurable with a peak flow meter, a device used to check how well your lungs are working) - The need to use a quick-relief inhaler more often For some people, asthma signs and symptoms flare up in certain situations: - Exercise-induced asthma, which may be worse when the air is cold and dry - Occupational asthma, triggered by workplace irritants such as chemical fumes, gases or dust - Allergy-induced asthma, triggered by airborne substances, such as pollen, mold spores, cockroach waste or particles of skin and dried saliva shed by pets (pet dander) When to see a doctor Seek emergency treatment Severe asthma attacks can be life-threatening. Work with your doctor to determine what to do when your signs and symptoms worsen - and when you need emergency treatment. Signs of an asthma emergency include: - Rapid worsening of shortness of breath or wheezing - No improvement even after using a quick-relief inhaler, such as albuterol - Shortness of breath when you are doing minimal physical activity Contact your doctor See your doctor: - If you think you have asthma. If you have frequent coughing or wheezing that lasts more than a few days or any other signs or symptoms of asthma, see your doctor. Treating asthma early may prevent long-term lung damage and help keep the condition from worsening over time. - To monitor your asthma after diagnosis. If you know you have asthma, work with your doctor to keep it under control. Good long-term control helps you feel better from day to day and can prevent a life-threatening asthma attack. - If your asthma symptoms get worse. Contact your doctor right away if your medication doesn't seem to ease your symptoms or if you need to use your quick-relief inhaler more often. Don't try to solve the problem by taking more medication without consulting your doctor. Overusing asthma medication can cause side effects and may make your asthma worse. - To review your treatment. Asthma often changes over time. Meet with your doctor regularly to discuss your symptoms and make any needed treatment adjustments. Causes It isn't clear why some people get asthma and others don't, but it's probably due to a combination of environmental and genetic (inherited) factors. Asthma triggers Exposure to various irritants and substances that trigger allergies (allergens) can trigger signs and symptoms of asthma. Asthma triggers are different from person to person and can include: - Airborne substances, such as pollen, dust mites, mold spores, pet dander or particles of cockroach waste - Respiratory infections, such as the common cold - Physical activity (exercise-induced asthma) - Cold air - Air pollutants and irritants, such as smoke - Certain medications, including beta blockers, aspirin, ibuprofen (Advil, Motrin IB, others) and naproxen (Aleve) - Strong emotions and stress - Sulfites and preservatives added to some types of foods and beverages, including shrimp, dried fruit, processed potatoes, beer and wine - Gastroesophageal reflux disease (GERD), a condition in which stomach acids back up into your throat Risk factors A number of factors are thought to increase your chances of developing asthma. These include: - Having a blood relative (such as a parent or sibling) with asthma - Having another allergic condition, such as atopic dermatitis or allergic rhinitis (hay fever) - Being overweight - Being a smoker - Exposure to secondhand smoke - Exposure to exhaust fumes or other types of pollution - Exposure to occupational triggers, such as chemicals used in farming, hairdressing and manufacturing Complications Asthma complications include: - Signs and symptoms that interfere with sleep, work or recreational activities - Sick days from work or school during asthma flare-ups - Permanent narrowing of the bronchial tubes (airway remodeling) that affects how well you can breathe - Emergency room visits and hospitalizations for severe asthma attacks - Side effects from long-term use of some medications used to stabilize severe asthma Proper treatment makes a big difference in preventing both short-term and long-term complications caused by asthma. Diagnosis Physical exam To rule out other possible conditions - such as a respiratory infection or chronic obstructive pulmonary disease (COPD) - your doctor will do a physical exam and ask you questions about your signs and symptoms and about any other health problems. Tests to measure lung function You may also be given lung (pulmonary) function tests to determine how much air moves in and out as you breathe. These tests may include: - Spirometry. This test estimates the narrowing of your bronchial tubes by checking how much air you can exhale after a deep breath and how fast you can breathe out. - Peak flow. A peak flow meter is a simple device that measures how hard you can breathe out. Lower than usual peak flow readings are a sign your lungs may not be working as well and that your asthma may be getting worse. Your doctor will give you instructions on how to track and deal with low peak flow readings. Lung function tests often are done before and after taking a medication called a bronchodilator (brong-koh-DIE-lay-tur), such as albuterol, to open your airways. If your lung function improves with use of a bronchodilator, it's likely you have asthma. Additional tests Other tests to diagnose asthma include: - Methacholine challenge. Methacholine is a known asthma trigger that, when inhaled, will cause mild constriction of your airways. If you react to the methacholine, you likely have asthma. This test may be used even if your initial lung function test is normal. - Nitric oxide test. This test, though not widely available, measures the amount of the gas, nitric oxide, that you have in your breath. When your airways are inflamed - a sign of asthma - you may have higher than normal nitric oxide levels. - Imaging tests. A chest X-ray and high-resolution computerized tomography (CT) scan of your lungs and nose cavities (sinuses) can identify any structural abnormalities or diseases (such as infection) that can cause or aggravate breathing problems. - Allergy testing. This can be performed by a skin test or blood test. Allergy tests can identify allergy to pets, dust, mold and pollen. If important allergy triggers are identified, this can lead to a recommendation for allergen immunotherapy. - Sputum eosinophils. This test looks for certain white blood cells (eosinophils) in the mixture of saliva and mucus (sputum) you discharge during coughing. Eosinophils are present when symptoms develop and become visible when stained with a rose-colored dye (eosin). - Provocative testing for exercise and cold-induced asthma. In these tests, your doctor measures your airway obstruction before and after you perform vigorous physical activity or take several breaths of cold air. How asthma is classified To classify your asthma severity, your doctor considers your answers to questions about symptoms (such as how often you have asthma attacks and how bad they are), along with the results of your physical exam and diagnostic tests. Determining your asthma severity helps your doctor choose the best treatment. Asthma severity often changes over time, requiring treatment adjustments. Asthma is classified into four general categories: Treatment Prevention and long-term control are key in stopping asthma attacks before they start. Treatment usually involves learning to recognize your triggers, taking steps to avoid them and tracking your breathing to make sure your daily asthma medications are keeping symptoms under control. In case of an asthma flare-up, you may need to use a quick-relief inhaler, such as albuterol. Medications The right medications for you depend on a number of things - your age, symptoms, asthma triggers and what works best to keep your asthma under control. Preventive, long-term control medications reduce the inflammation in your airways that leads to symptoms. Quick-relief inhalers (bronchodilators) quickly open swollen airways that are limiting breathing. In some cases, allergy medications are necessary. Long-term asthma control medications, generally taken daily, are the cornerstone of asthma treatment. These medications keep asthma under control on a day-to-day basis and make it less likely you'll have an asthma attack. Types of long-term control medications include: - Inhaled corticosteroids. These anti-inflammatory drugs include fluticasone (Flonase, Flovent HFA), budesonide (Pulmicort Flexhaler, Rhinocort), flunisolide (Aerospan HFA), ciclesonide (Alvesco, Omnaris, Zetonna), beclomethasone (Qnasl, Qvar), mometasone (Asmanex) and fluticasone furoate (Arnuity Ellipta). You may need to use these medications for several days to weeks before they reach their maximum benefit. Unlike oral corticosteroids, these corticosteroid medications have a relatively low risk of side effects and are generally safe for long-term use. - Leukotriene modifiers. These oral medications - including montelukast (Singulair), zafirlukast (Accolate) and zileuton (Zyflo) - help relieve asthma symptoms for up to 24 hours. In rare cases, these medications have been linked to psychological reactions, such as agitation, aggression, hallucinations, depression and suicidal thinking. Seek medical advice right away for any unusual reaction. - Long-acting beta agonists. These inhaled medications, which include salmeterol (Serevent) and formoterol (Foradil, Perforomist), open the airways. Some research shows that they may increase the risk of a severe asthma attack, so take them only in combination with an inhaled corticosteroid. And because these drugs can mask asthma deterioration, don't use them for an acute asthma attack. - Combination inhalers. These medications - such as fluticasone-salmeterol (Advair Diskus), budesonide-formoterol (Symbicort) and formoterol-mometasone (Dulera) - contain a long-acting beta agonist along with a corticosteroid. Because these combination inhalers contain long-acting beta agonists, they may increase your risk of having a severe asthma attack. - Theophylline. Theophylline (Theo-24, Elixophyllin, others) is a daily pill that helps keep the airways open (bronchodilator) by relaxing the muscles around the airways. It's not used as often now as in past years. Quick-relief (rescue) medications are used as needed for rapid, short-term symptom relief during an asthma attack - or before exercise if your doctor recommends it. Types of quick-relief medications include: - Short-acting beta agonists. These inhaled, quick-relief bronchodilators act within minutes to rapidly ease symptoms during an asthma attack. They include albuterol (ProAir HFA, Ventolin HFA, others) and levalbuterol (Xopenex). Short-acting beta agonists can be taken using a portable, hand-held inhaler or a nebulizer - a machine that converts asthma medications to a fine mist - so that they can be inhaled through a face mask or a mouthpiece. - Ipratropium (Atrovent). Like other bronchodilators, ipratropium acts quickly to immediately relax your airways, making it easier to breathe. Ipratropium is mostly used for emphysema and chronic bronchitis, but it's sometimes used to treat asthma attacks. - Oral and intravenous corticosteroids. These medications - which include prednisone and methylprednisolone - relieve airway inflammation caused by severe asthma. They can cause serious side effects when used long term, so they're used only on a short-term basis to treat severe asthma symptoms. If you have an asthma flare-up, a quick-relief inhaler can ease your symptoms right away. But if your long-term control medications are working properly, you shouldn't need to use your quick-relief inhaler very often. Keep a record of how many puffs you use each week. If you need to use your quick-relief inhaler more often than your doctor recommends, see your doctor. You probably need to adjust your long-term control medication. Allergy medications may help if your asthma is triggered or worsened by allergies. These include: - Allergy shots (immunotherapy). Over time, allergy shots gradually reduce your immune system reaction to specific allergens. You generally receive shots once a week for a few months, then once a month for a period of three to five years. - Omalizumab (Xolair). This medication, given as an injection every two to four weeks, is specifically for people who have allergies and severe asthma. It acts by altering the immune system. Bronchial thermoplasty This treatment - which isn't widely available nor right for everyone - is used for severe asthma that doesn't improve with inhaled corticosteroids or other long-term asthma medications. Generally, over the span of three outpatient visits, bronchial thermoplasty heats the insides of the airways in the lungs with an electrode, reducing the smooth muscle inside the airways. This limits the ability of the airways to tighten, making breathing easier and possibly reducing asthma attacks. Treat by severity for better control: A stepwise approach Your treatment should be flexible and based on changes in your symptoms, which should be assessed thoroughly each time you see your doctor. Then your doctor can adjust your treatment accordingly. For example, if your asthma is well-controlled, your doctor may prescribe less medicine. If your asthma isn't well-controlled or is getting worse, your doctor may increase your medication and recommend more-frequent visits. Asthma action plan Work with your doctor to create an asthma action plan that outlines in writing when to take certain medications or when to increase or decrease the dose of your medications based on your symptoms. Also include a list of your triggers and the steps you need to take to avoid them. Your doctor may also recommend tracking your asthma symptoms or using a peak flow meter on a regular basis to monitor how well your treatment is controlling your asthma. Lifestyle and home remedies Although many people with asthma rely on medications to prevent and relieve symptoms, you can do several things on your own to maintain your health and lessen the possibility of asthma attacks. Avoid your triggers Taking steps to reduce your exposure asthma triggers is a key part of asthma control, including: - Use your air conditioner. Air conditioning reduces the amount of airborne pollen from trees, grasses and weeds that finds its way indoors. 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 worsen nighttime symptoms by replacing certain items in your bedroom. For example, encase pillows, mattresses and box springs in dustproof covers. Remove carpeting and install hardwood or linoleum flooring. Use washable curtains and blinds. - Maintain optimal humidity. If you live in a damp climate, talk to your doctor about using a dehumidifier. - Prevent mold spores. Clean damp areas in the bath, kitchen and around the house to keep mold spores from developing. Get rid of moldy leaves or damp firewood in the yard. - 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. If you're likely to stir up dust, wear a mask or have someone else do the cleaning. - Cover your nose and mouth if it's cold out. If your asthma is worsened by cold or dry air, wearing a face mask can help. Stay healthy Taking care of yourself can help keep your symptoms under control, including: - Get regular exercise. Having asthma doesn't mean you have to be less active. Treatment can prevent asthma attacks and control symptoms during activity. Regular exercise can strengthen your heart and lungs, which helps relieve asthma symptoms. If you exercise in cold temperatures, wear a face mask to warm the air you breathe. - Maintain a healthy weight. Being overweight can worsen asthma symptoms, and it puts you at higher risk of other health problems. - Control heartburn and gastroesophageal reflux disease (GERD). It's possible that the acid reflux that causes heartburn may damage lung airways and worsen asthma symptoms. If you have frequent or constant heartburn, talk to your doctor about treatment options. You may need treatment for GERD before your asthma symptoms improve. Alternative medicine Certain alternative treatments may help with asthma symptoms. However, keep in mind that these treatments are not a replacement for medical treatment - especially if you have severe asthma. Talk to your doctor before taking any herbs or supplements, as some may interact with medications you take. While some alternative remedies are used for asthma, in most cases more research is needed to see how well they work and to measure the extent of possible side effects. Alternative asthma treatments include: - Breathing exercises. These exercises may reduce the amount of medication you need to keep your asthma symptoms under control. - Herbal and natural remedies. A few herbal and natural remedies that may help improve asthma symptoms include black seed, caffeine, choline and pycnogenol. 

Answer: A doctor will conduct a physical exam and potentially lung function tests to diagnose asthma. These tests will determine how much air moves in and out as you breathe. A chest X-ray and CT scan can identify structural issues or diseases that may be causing breathing problems. Allergy tests may also help a doctor diagnose the cause of your asthma.