Narcolepsy is a neurological condition where the brain is unable to regulate the body’s sleep-wake cycle. As a result, affected individuals usually feel energized as soon as they wake up in the morning but feel the urge to sleep several times a day. Narcolepsy doesn’t directly trigger serious long-term health conditions but can hamper one’s daily functioning significantly. Identifying the symptoms of narcolepsy early on can help with timely diagnosis and management of the disease.

Causes and triggers
The underlying biological cause of narcolepsy is the deficiency of hypocretin (also known as orexin), a brain chemical that regulates sleep. Scientists suggest that this hypocretin deficiency is caused by the immune system attacking specific brain regions that produce the brain chemicals. Apart from this, many possible factors may trigger or increase one’s risk of developing narcolepsy.

1. Hormonal changes
Puberty and adolescence may cause several hormonal changes in the body, which might trigger narcolepsy in some people.

2. Genetic factors
In most cases, narcolepsy is not inherited, but it does run in some families. Among those who develop narcolepsy due to genetic factors, a variation of the HLA-DQB1 gene is thought to trigger the condition.

3. Sudden, strong emotional outbursts
If a person experiences sudden, strong bouts of emotion, such as anger, fear, or excitement, they might develop cataplexy, a narcolepsy symptom that causes sudden, brief muscle weakness.

4. An infection
Sometimes, a pre-existing infection like swine flu (H1N1 influenza) or a streptococcal infection may also cause or increase one’s risk of narcolepsy.

5. High-stress levels
Individuals who experience high levels of stress due to personal or professional reasons may also develop cataplexy, which increases their chances of the condition’s onset.

Signs and symptoms

1. Excess sleepiness
Usually, a brain chemical called hypocretin (orexin) controls one’s sense of sleep and wakefulness. But, those with narcolepsy have hypocretin deficiency, which can disturb the sleep cycle considerably and cause one to feel lethargic and sleepy throughout the day.

2. Fluctuations in REM sleep
In the rapid eye movement (REM) stage, one’s eyes move rapidly in different directions while asleep. Typically, people enter the REM sleep stage around 60-90 minutes after they fall asleep, but those with narcolepsy enter this stage prematurely, usually within 15 minutes. Changes in brain activity may trigger REM sleep fluctuations.

3. Muscle weakness or cataplexy
Here, patients may suddenly lose their muscle tone, usually for a brief time period. Extreme emotional outbursts may trigger this symptom of narcolepsy.

4. Obstructive sleep apnea
In this case, one’s airways are partially or completely blocked, which might cause breathing problems and nonrestorative sleep, wherein one doesn’t feel energized even after hours of sleeping soundly.

5. Loss of appetite
Hypocretin deficiency causes severe loss of appetite, causing one to eat much less quantities of food than they usually do.

6. Sleep paralysis and hallucinations
In the case of sleep paralysis, one momentarily experiences loss of speech and movement while falling asleep or after waking up. Sometimes, sleep paralysis may also cause hallucinations, such as feeling the presence of a stranger in the room or perceiving objects that aren’t present. Sleep paralysis and hallucinations are experienced by many people with narcolepsy.