Why can't I sleep?

Insomnia can feel like a stubborn companion — one that keeps you tossing and turning while the rest of the world sleeps soundly. If you’ve ever found yourself staring at the ceiling wondering why sleep won’t come, you’re not alone. Nearly half of all adults in Australia report at least two sleep-related problems, and insomnia is one of the most common. But what actually causes insomnia, and what can you do about it?

What is insomnia?

Insomnia isn’t just about having trouble falling asleep. It can also mean waking up frequently during the night, rising too early, or not feeling refreshed even after what seems like enough sleep. As Dr Moira Junge, health psychologist and Chief Health Officer of the Sleep Health Foundation, explains:

“Sometimes it’s difficulty getting to sleep, sometimes difficulty staying asleep, waking too early, waking unrefreshed. Sometimes it can be a respiratory-related sleep disturbance like snoring. That’s what’s keeping people awake or keeping people sleepy during the day.”

Insomnia can be short-term, for example, triggered by a stressful event, or it can become a chronic issue that persists for months or even years.

What can cause insomnia?

Insomnia can be caused by a mix of factors: some within your control, and some that aren’t. Let’s break down some common causes.

1. Stress and mental health

Stress is a major contributor to insomnia. Worries about work, relationships, or health can keep your mind racing long after you’ve turned out the lights. Anxiety and depression are also closely linked to sleep problems.

READ MORE: Managing negative thinking before bed

2. Lifestyle habits

Certain habits can make it harder to fall and stay asleep:

• Consuming caffeine or alcohol too close to bedtime
• Smoking
• Eating heavy meals late at night
• Using electronic devices in bed

“Nicotine is not healthy at all,” Dr Junge elaborates, “and smoking before bed is a stimulant.”

Dr Junge adds that “minimal amounts of caffeine are OK, but approximately 6-7 hours before bed, and possibly longer for some people.”

READ MORE: Best foods for better sleep

Alcohol and sleep

For a restful night's sleep, avoid alcohol for at least four hours before bedtime. While it may make you feel sleepy initially, even small quantities of alcohol can disrupt your body's ability to reach deep, restorative sleep. Alcohol also acts as a diuretic, which may cause you to wake up more often to use the bathroom during the night.

3. Environmental factors

Your sleep environment plays a big role. Noise, light, and temperature can all disrupt sleep. Living near a busy road, having a noisy household, or sleeping in a room that’s too warm or too bright can make insomnia worse.

READ MORE: How to set up your bedroom for better sleep

4. Medical conditions and medications

Chronic pain, breathing problems, and other health issues can interfere with sleep. Some medications also have side effects that disrupt sleep.

5. Hormonal changes

Hormonal shifts in women can be associated with sleep problems. Life stages like pregnancy or menopause can bring changes that may lead to insomnia.

Insomnia in pregnancy

Insomnia is common during pregnancy and can be triggered by a range of factors including hormonal changes, nausea, needing to get up to use the bathroom, leg cramps, backaches, as well as stress. If sleep hygiene adjustments do not provide relief or you’re experiencing fatigue or anxiety from not getting enough sleep, talk to your GP about what treatment options may be best suited to you.

Insomnia in menopause

Many women experience sleep disturbances during perimenopause and menopause. This might look like finding it harder to fall asleep and stay asleep or waking early than you’d like. Changing hormones, sleep disorders, mental health challenges including anxiety and depression, and physical symptoms of menopause like hot flushes can all contribute to poor sleep quality during this stage of life. If sleep hygiene adjustments do not provide relief, reach out to your GP for support.

6. Sleep disorders

Sometimes, insomnia is a symptom of a sleep disorder such as sleep apnoea or restless leg syndrome. These conditions require specific treatment and support.

READ MORE: When you can't sleep next to your partner

What you can do to improve your sleep

While some causes of insomnia are out of your control, there are steps you can take to improve your sleep:

• Create a relaxing bedtime routine
• Limit caffeine, alcohol, and nicotine, especially in the evening
• Make your bedroom quiet, dark, and cool
• Avoid heavy meals and screen time before bed
• Practice mindfulness or gentle exercise during the day

Whatever you choose to do, it’s important to go in with the right attitude, and be patient.

“Manage expectations of sleep and of yourself and don’t put too much pressure or be too rigid about any one strategy,” advises Dr Junge. “It’s going to take some time; it’s a process.”

Want more tips for better sleep? Visit our checklist for better sleep hygiene.

When to seek help

It’s normal to have the occasional bad night, but persistent sleep problems can affect your mood, health, and daily life.

If you notice excessive daytime sleepiness, severe snoring, or you’re waking up unrefreshed even with enough sleep time, it may be time to reach out for support.

“If it’s affecting your quality of life, you need to talk to a trusted health professional,” Dr Junge advises.

A check in with your GP is often the best place to start, as they will be able to assess your individual situation and recommend the best next steps to support you.

Support when you need it

Insomnia can be challenging, but understanding what can cause it is the first step toward better sleep. Whether it’s stress, lifestyle habits, or medical issues, there are ways to address insomnia and improve your sleep health.