Asthma at night
Symptoms of asthma at night
Asthma at night, also known as nocturnal asthma, can be a frightening experience for a person, waking up short of breath, wheezing and coughing.
As well as disturbing sleep and leaving a person tired the next day, this common condition is serious, increasing the risk of complications from asthma.
Asthma at night requires proper diagnosis and effective treatment.
Nocturnal asthma attacks can cause daytime sleepiness, fatigue and irritability.
These problems can affect a person's quality of life as well as making it harder to manage daytime asthma symptoms.
Asthma at night causes
The exact reasons for why asthma is worse during sleep are not known. There are though many explanations for what may cause nocturnal asthma. Some of these may involve increased exposure to allergens at night, cooling of the airways, the reclining position, or hormone secretions that follow a circadian pattern or rhythm. Sleep itself may even cause changes in bronchial function.
Causes may include:
Increased mucus or sinusitis
During sleep, the airways tend to narrow and mucus builds up in swollen airways. This can trigger night-time coughing, which can cause more tightening of the airways. Increased drainage from your sinuses can also trigger asthma in highly sensitive airways. Sinusitis with asthma is quite common.
Asthma problems may occur during sleep regardless of when the sleep is taking place. People with asthma who work during the night may have breathing attacks during the day when they are sleeping. Most research suggests that breathing tests are worse about four to six hours after you fall asleep. This suggests there may be some internal trigger for sleep-related asthma.
Lying in a reclining position may also predispose you to night-time asthma problems. Many factors may cause this, such as accumulation of secretions in the airways (drainage from sinuses or postnasal drip), increased blood volume in the lungs, decreased lung volumes, and increased airway resistance.
Breathing colder air at night or sleeping in an air‑conditioned room, such as a hotel room, may also cause loss of heat from the airways. Airway cooling and moisture loss are important triggers of exercise‑induced asthma. They are also implicated in night-time asthma. This may be experienced when staying in hotels where air conditioning is common, so where possible switch air conditioning off.
Gastro-oesophageal reflux disease (GORD)
If you are frequently troubled by heartburn, the reflux of stomach acid up through the oesophagus to the larynx may stimulate a reflex associated with a bronchial spasm. This acid reflux is worse when you lie down and if you take certain medicines for asthma, which relax the valve between the stomach and the oesophagus. Sometimes, acid from the stomach will irritate the lower oesophagus and may activate the vagus nerve, which sends signals to the bronchial tubes that result in bronchoconstriction. If acidic gastric juice regurgitates all the way up the oesophagus to the back of the throat and some of it drips down into the trachea, bronchi and lungs a severe reaction may take place. This can involve airway irritation, increased mucous production, and bronchoconstriction. Taking care of GORD and asthma with appropriate medications can often stop night-time asthma.