What Is Insomnia?
Insomnia is a sleep disorder in which you have trouble falling asleep, staying asleep, or waking up too early.
The condition can be short term (acute) or can last a long time (chronic). It may also come and go.
Acute insomnia lasts from one night to a few weeks. Insomnia is chronic when it happens at least three nights a week for three months or more.
Adults need seven to nine hours of sleep every day. While experts don’t yet fully understand sleep’s effects on the body, it is clear that getting inadequate sleep can do more than just make you feel tired during the day. Over time, it can be a threat to your health. For example, poor sleep has been linked to serious health problems such as high blood pressure, heart attack, and depression.
Types of Insomnia
There are two types of insomnia: Primary and secondary.
Primary insomnia. This means your sleep problems aren’t linked to any other health condition or problem.
Secondary insomnia. This means you have trouble sleeping because of a health condition (like asthma, depression, arthritis, cancer, or heartburn), pain, medication, or substance use (like alcohol).
You might also hear about:
Sleep-onset insomnia. This means you have trouble getting to sleep.
Sleep-maintenance insomnia. This happens when you have trouble staying asleep through the night or wake up too early.
Mixed insomnia. With this type of insomnia, you have trouble both falling asleep and staying asleep through the night.
Paradoxical insomnia. When you have paradoxical insomnia, you underestimate the time you’re asleep. It feels like you sleep a lot less than you really do.
What Causes Insomnia?
The causes depend on whether you have primary insomnia or secondary insomnia, also called comorbid insomnia because it develops as a result of another health condition. Many of these causes can be addressed, such as lifestyle habits and treating ongoing medical problems. However, some causes can’t be changed, such as your genes.
Causes of primary insomnia include:
- Stress related to big life events, like a job loss or change, the death of a loved one, divorce, or moving
- Your sleep environment, or the things around you while you are trying to sleep, like noise, light, or a room temperature that’s either too hot or too cold for you to sleep comfortably
- Changes in your sleep schedule like jet lag, a new shift at work, waking up to care for a new baby, or moving to a new home
- Your genes, as research has found that a tendency for insomnia may run in families
- Eating too close to bedtime, which can leave you feeling quite uncomfortable when lying in bed and prevent sleep, as can heartburn, which also may happen after overeating
- Caffeine and nicotine, which are both stimulants and can keep you up if you consume them too soon before bedtime
- Alcohol, which can interfere with your ability to get deep, restful sleep and may cause you to wake up during the night
- Not getting enough exercise or other physical activity in the daytime
- Related:How to Fall Asleep Quickly
Your sleep habits, or sleep hygiene, play a major role in how well you sleep. The following habits can lead to insomnia:
- Going to bed at different times rather than sticking to a regular sleep schedule
- Waking up at different times from day to day
- Taking naps during the day
- Being very active and having too little time to relax before your bedtime
- Working, eating, or watching TV in bed
- Too much screen time with your phone, TV, computer, or video games right before you try to fall asleep
If you share a bed with someone, that person’s habits can affect your sleep. For example, if they snore, you might not be able to sleep.
Secondary causes of secondary insomnia include:
- Mental health issues like depression and anxiety
- Certain prescription and over-the-counter medications, including some for colds, allergies, depression, high blood pressure, and asthma
- Pain or discomfort at night, such as that caused by back pain or arthritis
- Substance use disorders, such as drug and alcohol abuse
- Hyperthyroidism, or an overactive thyroid gland
- Other sleep disorders, like sleep apnea or restless legs syndrome
- Hormone changes that happen during menstruation, pregnancy, and menopause
- Alzheimer’s disease and other types of dementia
- ADHD
- Parkinson’s disease
- Cancer
- Diabetes
- Heart disease
- Benign prostatic hyperplasia
- Gastroesophageal reflux disease
- Chronic obstructive pulmonary disease
- Epilepsy
Insomnia Risk Factors
Insomnia affects women and people assigned female at birth (AFAB) more than men and people assigned male at birth and older people more than younger ones. Young and middle-age African Americans also have a higher risk of insomnia.