Asthma is a chronic lung disease that causes shortness of breath, wheezing, chest tightness, and cough. More than 25 million adults and children live with asthma in the United States.
People with nocturnal asthma, or nighttime asthma, experience symptoms while sleeping. This can disrupt sleep. It can also make managing asthma more difficult. Up to 60% of asthma patients are estimated to have nocturnal asthma.
An asthma attack at night is a sign of uncontrolled asthma. If you experience asthma symptoms at night more than two times per month, make an appointment with a doctor. You may want to see an asthma specialist, such as an allergist or pulmonologist.
What causes nocturnal asthma?
What causes nocturnal asthma is not completely understood. However, several factors can make asthma more severe at night.
When you breathe in, the lungs transport oxygen into the bloodstream. From there it is carried to the rest of the body. When you breathe out, the lungs send the waste, or carbon dioxide, out of the bloodstream. How well this process works varies – it is part of the body’s natural circadian rhythm. The circadian rhythm is your internal clock. It regulates the body over a 24-hour period.
Lungs work best during the day, with peak lung function at about four in the afternoon. Studies show lung function drops by 4 a.m., especially in people with asthma. The fluctuation is usually less than 10 percent in most people. But people with asthma can have up to a 50 percent variation from day to night.
The body’s inner clock, or circadian rhythm, affects hormones such as adrenaline, cortisol, and melatonin. The hormones change throughout the day and can trigger nighttime asthma symptoms.
- Adrenaline is naturally lower during the night. It helps to relax and keep the airways open.
- Cortisol also goes down at night, and this can affect airway narrowing and worsen asthma symptoms.
- Melatonin is higher at night and is associated with a decrease in lung function.
The circadian rhythm can also affect levels of airway inflammation. This leads to nighttime asthma symptoms.
In addition, mucus from post-nasal drip, allergens, and cold air can trigger nighttime asthma attacks.
What are nocturnal asthma symptoms?
Nighttime asthma symptoms mirror daytime asthma symptoms, but are usually worse. People with nocturnal asthma often experience:
- coughing
- shortness of breath
- wheezing
- chest tightness
These symptoms can occur just before or even during sleep, and can lead to poor sleep quality. The nocturnal symptoms can cause irritability and tiredness and may also worsen asthma symptoms during the day.
Nocturnal asthma can be very serious. An asthma attack at night can be fatal. Shockingly, over half of all deaths from asthma attacks happen between midnight and 8 am.
Daytime effects of nocturnal asthma
Nocturnal asthma and allergy symptoms go beyond the bedroom. Children with nighttime asthma miss more school days than healthy kids. It can also cause parents to miss work. School and work performance can suffer when the family can’t sleep.
Children with nocturnal asthma often perform poorly in school. Research suggests these children score lower on memory and timed tests. They often have an inability to concentrate, listen and problem solve. Poor sleep from asthma can include morning headaches and mood changes. They may have an increased risk of getting colds and the flu.
Nocturnal asthma triggers
Physiological changes that occur during sleep contribute to nocturnal asthma. But there are other nighttime asthma triggers, including:
- Mucus and postnasal drip. At night, people often experience increased mucus production, sinus drainage and acid production. This fluid and acid can trigger asthma symptoms and make asthma at night worse.
- Sleep position. Sleeping on your back can allow fluids to pool in breathing passages. This can trigger nocturnal asthma.
- Comorbid conditions. Gastroesophageal reflux disease (GERD), acid reflux, obstructive sleep apnea, allergic rhinitis, and obesity are common comorbid conditions and can make asthma worse.
- Allergens. Exposure to indoor allergens, such as dust mites, pet dander, or mold, can trigger symptoms.
- Cold air. Sleeping with air conditioning on or with a window open can trigger symptoms. Cool air is a common asthma trigger.
- Smoking. Cigarette smoke is a known trigger, whether it’s from smoking before bedtime or from secondhand smoke.
How do you treat nocturnal asthma?
Make sure to take your asthma medications daily. Treatment may include:
- Quick-relief inhalers. These open airways to relieve asthma symptoms. They can be taken at the first sign of asthma symptoms for quick relief, even at night. There is also a quick-relief inhaler available that can relieve symptoms and also reduce airway inflammation.
- Controller medications (anti-inflammatory). These reduce and prevent lung inflammation. They include inhaled corticosteroids (ICS), long-acting inhaled beta2-agonists (LABA) and long-acting muscarinic antagonists (LAMA). Controller medications are taken every day, not just when you have symptoms.
- Leukotriene modifiers. Theseblock the action of leukotrienes, chemicals involved in immune responses that lead to inflammation and tightening of the airways.
- Combination inhalers. These include more than one asthma medication in one device. For example, a combination inhaler may include ICS and LABA. Another combination is ICS and LAMA.
- Biologics target the specific cells and pathways that cause inflammation and asthma symptoms. These medications treat severe asthma.
To manage nighttime asthma, avoid triggers and treat other illnesses. Also, avoid using nasal sprays and inhalers with stimulants before bed. They can make falling asleep harder.
For people with allergic asthma, doctors may recommend allergen immunotherapy.
People with asthma should meet with an asthma specialist to develop an Asthma Action Plan. This plan can be used for both day and night symptoms.
Questions and Answers (Q&A) on Nocturnal Asthma
Below are some frequently asked questions about nocturnal asthma. If you have a specific question you’d like answered here, please Email Gary Fitzgerald, Senior Editor.
Reviewed by:
Bradley Chipps, MD, FACAAI, is a board-certified allergist and pediatric pulmonologist with Capital Allergy and Respiratory Disease Center in Sacramento, California. He earned his medical degree from University of Texas Medical Branch in Galveston in 1972. He is Past President of the American College of Allergy, Asthma and Immunology (ACAAI).