While most people consider "wheezing" the key sign of asthma, there are also other, more unusual asthma symptoms. For instance, a dry, hacking cough that persists may actually be a symptom of asthma. Chest tightness and difficulty breathing in the early morning hours can also be asthma symptoms. Likewise, constant sighing may be associated with asthma.
Unusual asthma symptoms may include:
- rapid breathing
- fatigue; inability to exercise properly
- difficulty sleeping
- anxiety; difficulty concentrating
- chronic cough without wheezing (cough-variant asthma)
To complicate matters, asthma symptoms are not consistent and often vary from time to time in an individual. As an example, you might experience asthma primarily at night -- known as nocturnal asthma -- rather than during the day. Furthermore, episodes of asthma can be triggered by many different factors such as allergens, dust, smoke, cold air, exercise, infections, medications, and acid reflux. Finally, other health conditions such as heart failure, bronchitis, and dysfunction of the vocal cords can cause symptoms that mimic those of asthma, yet these conditions are not asthma. For these reasons, accurately diagnosing and effectively treating asthma can be a challenge for you and your asthma health care provider.
Can Cough Be the Only Symptom of Asthma?
Chronic cough or a cough that lasts longer than three weeks may be caused by the following:
- postnasal drip
- cigarette smoking
- acid reflux
- heart disease
- medications such as ACE inhibitors used for treating high blood pressure
- lung cancer
A chronic cough may be an unusual symptom of asthma. The cough may first appear after a cold or an upper respiratory tract infection. The cough may also start as a "tickle" in the throat. In some people with asthma, laughing or exercise triggers coughing. Other people cough at night while others cough at any time of day without a trigger.
Coughing due to asthma usually does not respond to cough suppressants, antibiotics, or cough drops but will respond to asthma medications. If you have a cough that does not get better on its own within 3 to 6 weeks, see your health care provider.
For more information, see WebMD's article on Cough-Variant Asthma.
Nighttime (Nocturnal) Asthma
Nighttime (nocturnal) asthma is a very common type of asthma, with more than 90% of asthma patients experiencing nighttime wheezing and coughing. Symptoms of asthma are most common between midnight and 8 a.m. and can cause insomnia and sleep deprivation among people with asthma. In fact, sleep disturbances in people with asthma usually mean that their asthma is inadequately controlled and warrants a visit to the doctor to re-evaluate the prescribed asthma medications.
Lung function in a person with asthma can decline by up to 50% during an episode of nocturnal asthma. The reasons are not clear, but possible explanations include:
- Exposure to allergens at night such as dust mites or animal dander
- Changes in the levels of hormones such as cortisol, histamine, and epinephrine at night, resulting in increased reactivity of the airways
- Longer periods of exposure to asthma triggers within the bedroom
- Reflux of stomach acid into the esophagus (GERD) related to laying down (heartburn and asthma)
- A late reaction to daytime asthma triggers
- Cooling of the airways that cause spasm of the major airways
- Sinusitis and postnasal drip
- Sleep apnea
It is possible to test for nocturnal asthma by taking measurements of airflow out of the lungs while exhaling (peak flow) in the evening and again upon awakening in the morning. This is done with an asthma test called a peak flow meter -- a small, portable meter that measures the flow of air. (An asthma specialist can demonstrate the correct technique for making these measurements.) A greater than 20% decrease in the peak flow measurement from the evening to the morning suggests nocturnal asthma.
For more information, see WebMD's article on Nocturnal Asthma.
Health Conditions That Mimic Asthma
Other health conditions can mimic asthma, which makes the correct diagnosis of asthma more difficult for your doctor.
For more information, see WebMD's article on Health Conditions That Mimic Asthma.
Cardiac asthma is one of the conditions that mimics asthma and usually occurs in elderly people who have wheezing and shortness of breath because of heart failure. When the heart is too weak to pump blood effectively, fluid will accumulate in the lungs and cause shortness of breath and wheezing. A chest X-ray can help diagnose heart failure by showing an enlarged heart (usually a sign of heart failure) along with fluid in the tissues of the lung. Treatment of heart failure involves using diuretics (water pills) to rid the lungs of excess fluid and medications to help the heart muscle pump more effectively. When heart failure is controlled, the wheezing will stop. Some people may suffer from asthma and heart failure simultaneously. These patients require treatment for both health conditions to improve their quality of life.
Asthma and Other Allergic Reactions
Inhaled mold spores and particles from bird droppings and feathers (such as from parrots) can cause allergic reactions in the airways and lungs. For example, when the fungus Aspergillus causes an allergic reaction in the airways, the condition is called allergic bronchopulmonary aspergillosis. Affected individuals usually have asthma. Treatment involves opening the airways with bronchodilators and decreasing inflammation with steroids over a prolonged period of time. When the lung tissues develop an allergic reaction to inhaled bacteria, fungi, or bird particles, the condition is called hypersensitivity pneumonitis. This condition is differentiated from acute asthma by the lack of wheezing, the presence of a fever, and the pattern of pneumonia on the chest X-ray. Hypersensitivity pneumonitis is treated by avoiding the allergens and taking steroids.
Exercise is a common trigger for asthma and may cause symptoms such as chest tightness, shortness of breath, and coughing in 80% to 90% of people with asthma. The asthma symptoms usually start about 10 minutes into the exercise or 5 to 10 minutes after completing the activity, although some people experience symptoms about four to eight hours after exercise. Exercise-induced asthma may affect all ages, but it's most common in kids with childhood asthma and young adults. All athletes, from weekend warriors to professionals and Olympians, can be affected by exercise-induced asthma.
For most asthma patients, exercise-induced asthma is treatable and preventable, allowing children and adults with asthma to fully participate in sports and exercise. Regular exercise is beneficial for the heart, circulatory system, muscles (including breathing muscles), and mental health. However, regular exercise is not a cure for asthma.
Exercise-induced asthma is diagnosed by a pattern of asthmatic symptoms prompted by exercise. When the diagnosis is unclear, it can be confirmed in a doctor's office by performing breathing tests at rest and after exercise.
Health Conditions That May Worsen Asthma
Gastroesophageal Reflux Disease (GERD)
GERD is a common condition caused by the regurgitation (reflux) or backwash of stomach acid into the esophagus from the stomach. At times, the acid even may regurgitate into the back of the throat and reach the lungs. GERD usually -- but not always -- is associated with a burning discomfort under the breastbone, called heartburn, which occurs mostly after meals or when lying down. In some people the symptom of acid reflux is not heartburn. Instead, they experience coughing, wheezing, hoarseness, or sore throat.
The presence of acid in the esophagus or the passage of acid into the lungs (aspiration) may cause the bronchial tubes to constrict (bronchospasm), causing wheezing and coughing that may not respond to medications for asthma. Bronchospasm related to acid reflux tends to occur more frequently at night as a result of lying down. Interestingly, GERD is common among patients with asthma. Some doctors believe that asthma itself or asthma treatments in some way make people with asthma more susceptible to acid reflux. For example, theophylline, an oral asthma medication (bronchodilator) that's occasionally used to treat asthma, may promote acid reflux by relaxing the specialized muscles in the esophagus that normally tighten to prevent regurgitation of acid.
In people with nighttime asthma or difficult to control asthma, treating acid reflux may help relieve coughing and wheezing. Treatment of GERD involves elevating the head of the bed, losing weight, avoiding spicy food, caffeine, alcohol, and cigarettes. Proton pump inhibitors such as Prilosec, Protonix, Aciphex, Prevacid, and Nexium are potent inhibitors of production of acid in the stomach and are effective treatments for asthma aggravated or caused by acid reflux. Rarely, surgery is performed to prevent acid reflux for people with severe GERD that does not respond to medications.
For more information, see WebMD's article on Heartburn and Asthma.
Allergic Rhinitis and Asthma
There is a clear association between allergic rhinitis (hay fever) and asthma. The question of which comes first -- the allergic rhinitis or the asthma -- is not easily answered. Allergic rhinitis is considered a risk factor in developing asthma -- up to 78% of those with asthma also have allergic rhinitis.
Many people with asthma recall developing their asthma and nasal symptoms (sneezing, congestion, a runny nose, and itchiness in the nose) at or about the same time. Others developed their asthma either before or after the onset of their allergic rhinitis. We now know that almost all people with allergic asthma also have allergic rhinitis. Allergic asthma is the most common type of asthma. Additionally, roughly one third of persons with allergic rhinitis will develop asthma. People with both conditions can expect to suffer more severe asthma attacks and require stronger medications to prevent their asthma symptoms. People with allergic rhinitis should be vigilant about reporting any persistent coughing or wheezing to their doctors. Sometimes allergy tests are done to isolate allergy and asthma triggers and allergy shots (immunotherapy) are given to reduce asthma symptoms. In addition, the presence of asthma can easily be determined with lung function tests.
The possible reasons why allergic rhinitis and asthma are related are that:
- The nasal and bronchial membranes are made up of almost the same type of tissue.
- The nerves of the upper airway (nasal cavity) and the lower airway (bronchial tubes) are connected. Both the upper and lower airways are exposed to the same external environment during breathing. When allergens reach the nasal cavity there is stimulation of nerve endings in the nasal cavity. This stimulation causes reflex neural signals to be sent to the tissues of both the nasal cavity and the lower airways. In the nasal cavity, these signals cause accumulation of fluid and the formation of mucus, while in the bronchial tubes they cause bronchial constriction and possibly acute asthma. This is sometimes referred to as the naso-bronchial reflex.
- Nasal congestion causes mouth breathing. During mouth breathing, air bypasses the nose. The air is not filtered for allergens and irritating particles, and it is not warmed or humidified. This non-conditioned air is more likely to cause bronchial hyper-reactivity and result in asthma symptoms.
- Mucus from the nasal cavity may drip from the back of the nose into the throat, especially during sleep. This dripping mucus triggers bronchial inflammation and causes episodes of asthma at night.
For more information, see WebMD's article on Allergies and Asthma.
Sinusitis and Asthma
Over the years, doctors have noted an association between asthma and sinusitis. In fact, 15% of patients with sinusitis also have asthma (as opposed to 5% of the normal population). An astounding 75% of severely asthmatic patients also have sinusitis. Additionally, asthmatic patients often report that their symptoms worsen when they develop sinusitis. Conversely, when the sinusitis is treated, the asthma improves.
The reasons behind the association of asthma and sinusitis include:
- Sinusitis may activate a "sinobronchial reflex" and worsen asthma.
- The infected mucus from the sinuses may drain into the bronchial tubes and cause inflammation that results in bronchitis (sinobronchitis). This can worsen asthma.
For in-depth information, see WebMD's Sinusitis and Asthma.