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While overeating, overdrinking, and viral infections are well-known primary causes of nausea, did you know that lack of sleep can also trigger it? Insufficient sleep can disrupt the autonomic nervous system and hormone balance, leading to a decline in digestive function.
This article explains the causes and mechanisms of nausea due to lack of sleep. It also introduces ways to cope with and prevent nausea caused by sleep deprivation, so please use it as a reference.
Why does lack of sleep cause nausea?
If you experience nausea due to lack of sleep, it may not be the sole cause. Nausea may be caused by a combination of factors, such as those listed below, which can lead to an imbalance in the autonomic nervous system.
- Stress, such as lack of sleep
- Disrupted lifestyle
- Poor physical condition
- Snoring and sleep apnea syndrome
- Side effects of medication
Stress, such as lack of sleep
When you are sleep-deprived or under mental stress, a large amount of "cortisol" is secreted. Cortisol is a hormone that plays a role in glucose production, fat breakdown, metabolism promotion, and suppressing inflammation such as fever and swelling.
When you are sleep-deprived or under stress, cortisol secretion rapidly increases to cope with it, which excites the sympathetic nervous system. When the sympathetic nervous system is activated, a part of its response is a decrease in digestive function, which can lead to nausea.
Disrupted lifestyle
Irregular sleep and an unbalanced diet, among other lifestyle disruptions, are also causes of nausea.
Irregular lifestyle habits and an unbalanced diet can disrupt the autonomic nervous system. The autonomic nervous system is the nerve system that controls bodily functions. It also plays a role in regulating the amount of stomach acid, so if the balance of the autonomic nervous system is disrupted by an irregular lifestyle, symptoms of nausea may appear.
Poor physical condition
Poor physical condition is also a cause of nausea. In addition to the effects of viruses, prolonged poor physical condition can disrupt the autonomic nervous system, making you more prone to nausea. Furthermore, a disrupted autonomic nervous system can lead to shallow sleep, causing symptoms similar to sleep deprivation even after sleeping for a long time.
Snoring and sleep apnea syndrome
Individuals who snore or have sleep apnea syndrome tend to experience nausea more frequently.
This is because prolonged presence of these symptoms weakens the "lower esophageal sphincter," which is a muscle in the esophagus. The lower esophageal sphincter prevents stomach acid from flowing back up, so if this muscle weakens, you are more likely to experience nausea and an upset stomach.
Side effects of medication
Nausea can also be a side effect of medication, so if you take medication frequently, this could be a contributing factor. Particularly, when taking strong medication, when not feeling well, or when the autonomic nervous system is disrupted, the side effects can be more pronounced.
Negative effects of sleep deprivation on the body
In addition to nausea, lack of sleep can have the following negative effects on the body:
- Decreased motivation and judgment
- Decreased organ function
- Decreased immune function
- Increased appetite
Decreased motivation and judgment
When sleep-deprived, the function of the frontal lobe in the brain declines. The frontal lobe is the foremost part of the cerebrum, which constitutes most of the brain. It primarily governs thought, motivation (spontaneity), emotions, personality, and reason, so a decline in frontal lobe function leads to decreased motivation and judgment.
Decreased organ function
When sleep deprivation persists, the autonomic nervous system becomes unstable. The autonomic nervous system plays a crucial role in regulating the functions of the digestive system, such as gastrointestinal peristalsis and gastric acid secretion. Therefore, if sleep deprivation persists due to insufficient or irregular sleep, or poor sleep quality, the balance of the autonomic nervous system is disrupted, leading to a decline in organ function.
Decreased immune function
During sleep, "growth hormone" is secreted, which supports immune function and helps repair and regenerate cells. However, if growth hormone is not sufficiently secreted due to sleep deprivation, immune function decreases, for reasons such as reduced production of immune substances and decreased activity of NK (natural killer) cells, which play a role in attacking viruses, leading to a state where one is more susceptible to infections.
Increased appetite
Chronic sleep deprivation also affects appetite. According to data from the Ministry of Health, Labour and Welfare, just two days of 4-hour sleep led to an increase in appetite compared to a day with 10 hours of sleep. This is because the secretion of "leptin," a hormone that suppresses appetite, decreases, while the secretion of "ghrelin," a hormone that increases appetite, increases.
Reference: Deep Relationship Between Sleep and Lifestyle Diseases | e-Health Net (Ministry of Health, Labour and Welfare)
As such, sleep deprivation also affects the hormone balance that regulates appetite, so if sleep deprivation persists, it can lead to overeating and increased snacking, potentially causing weight gain.
Coping with and preventing nausea caused by lack of sleep
The main ways to cope with and prevent nausea caused by lack of sleep are as follows:
- Rest
- Drink water or milk
- Eat easily digestible foods
- Limit consumption of luxury foods
- Maintain a healthy body weight
- Get quality sleep
Rest
When you feel nauseous, it's important to rest first. Even a short break can alleviate symptoms. However, lying down can make nausea worse by making stomach acid more likely to reflux, so it's recommended to rest while sitting in a chair.
Drink water or milk
When the balance of the autonomic nervous system is disrupted due to lack of sleep, excessive gastric acid is secreted, which can lead to gastrointestinal symptoms such as indigestion, heartburn, stomach pain, and nausea.
In such cases, drinking water or milk is effective. Diluting stomach acid can help alleviate symptoms. Milk, in particular, is recommended because it helps protect the esophageal lining from stomach acid.
Eat easily digestible foods
If you regularly consume foods that strain your stomach, you'll be more prone to nausea even when feeling generally unwell. In particular, be careful not to overeat fatty foods, fried foods, sugary items, citrus fruits, and spicy foods, as they slow down digestion and put a strain on the stomach.
To prevent nausea, it's important to always choose easily digestible foods. By selecting foods that are low in sugar, fat, and irritants, and are soft and quickly digestible, you can help maintain normal stomach function.
Limit consumption of luxury foods
Luxury foods such as alcohol, coffee, and tobacco are also causes of uncomfortable gastrointestinal symptoms. Excessive consumption of alcohol and coffee, as well as smoking, can lead to excessive gastric acid secretion. Smoking also reduces the resistance of the gastric mucosa, making stomach pain more likely. It is advisable to consume luxury foods in moderation, and if gastrointestinal symptoms appear frequently, consider quitting smoking.
Maintain a healthy body weight
People who are obese tend to have increased abdominal pressure due to fat, making stomach acid more likely to reflux. Also, overeating and eating too quickly can increase internal stomach pressure, which can also cause stomach acid reflux.
Therefore, improving your diet and maintaining a healthy body weight is one way to prevent nausea. Preventing an increase in abdominal and internal stomach pressure and creating an environment where stomach acid is less likely to reflux may help prevent nausea.
Get quality sleep
Even if you get enough sleep, if the quality of your sleep is poor, such as shallow sleep, you may experience symptoms similar to sleep deprivation. Sleep quality can be improved by maintaining a regular lifestyle, exercising moderately, and reviewing your diet, bathing habits, and sleep environment.
The following article introduces 10 ways to improve sleep quality; try implementing what you can.
How to Improve Sleep Quality? Also Explains How Quality is Determined and Causes of Decline
Could nausea from lack of sleep be a sign of illness?
Chronic sleep deprivation can make you more susceptible to lifestyle-related diseases, so caution is advised. In fact, it is known that people with chronic sleep deprivation are more likely to suffer from lifestyle-related diseases such as diabetes and coronary artery diseases like myocardial infarction and angina pectoris.
If you experience stomach pain, rapid weight loss, or other symptoms in addition to nausea, it is recommended to visit a medical institution.
Review your sleep environment to relieve nausea caused by lack of sleep
Lack of sleep can disrupt the autonomic nervous system and hormone balance. Since these affect stomach and intestinal function, their disruption can lead to unpleasant stomach symptoms such as nausea and discomfort.
To relieve nausea and other unpleasant stomach symptoms caused by lack of sleep, it is important to review your lifestyle habits, including diet, exercise, and bathing, and to get enough high-quality sleep. Start with what you can to ensure you feel well both mentally and physically.
