By Sukriti Wahi Wellness 14.08.2026

This Is Why You're Waking Up Tired, Even After 8 Hours of Sleep

Persistent exhaustion? A doctor explains the most common reasons why we're not reaping the full benefits of bedtime.

Sleeping the medically recommended seven to nine hours per night and still waking up tired might be among one of the more frustrating things in life. After all, sleep – and a lack thereof – plays a fundamental role in so many of our vital functions.

“Quality sleep is essential because it allows your brain and body to repair, regulate hormones, consolidate memories, and maintain immune function. Without it, even long hours in bed won’t restore energy or focus,” says Sydney-based General Practitioner, Dr Andrew Noussair. Putting in the (bed) time but rising without the “shine”? There may be a few possible reasons for that.

Here, Dr Noussair weighs in on some of the factors that might be keeping you from feeling refreshed upon waking (and what you can do about it).

1. Poor sleep quality

When it comes to sleep (and most things in life), quantity doesn’t replace quality. So, if you’re technically tallying “enough” hours of sleep per night but find yourself repeatedly waking or tossing and turning, the issue might lie with the type and quality of sleep you’re getting.

“Light or interrupted sleep can prevent the body from entering deep, restorative sleep stages (like slow-wave) and REM sleep,” Dr Noussair tells Bed Threads Journal.

“To fix it, try tracking your sleep using an app or device and create a quiet, dark and cool sleep environment to minimise disruptions.”

2. Stress or anxiety

Doomscrolling before bed? Tend to put all stressors of the day onto your pillow? Unfortunately, both stress and anxiety can do a number on our sleep and drain us before the next day even begins.

“Mental tension activates the nervous system, increasing heart rate and cortisol levels, which interfere with falling and staying asleep,” explains Dr Noussair.

“Try relaxation techniques like deep breathing, journalling, or meditation before bed, and consider cognitive behavioural therapy if stress is chronic.”

3. Poor sleep hygiene

With all the unexpected things the day can throw at us, it can be easy to let our bedtime routines and sleep hygiene fall to the wayside. Unfortunately, however, it could be at the expense of our ability to function optimally the next morning.

“Habits like irregular bedtimes, using screens late at night, or consuming caffeine and alcohol close to bedtime can prevent deep sleep,” says Dr Noussair.

The fix? Dr Noussair recommends setting a consistent sleep schedule, avoiding screens an hour before bed, and limiting caffeine and alcohol in the evening.

4. Nutritional deficiencies

If your sleep quality has been suffering and you’ve been waking up exhausted, it’s worth getting a blood test to check for any potential nutritional deficiencies that could be impacting your energy levels.

“Low iron, vitamin B12, or vitamin D can cause fatigue and impair neurological function, affecting overall energy and sleep restoration. Get a blood test to check nutrient levels and then improve your diet or take supplements as recommended by your doctor,” says Dr Noussair.

5. Circadian rhythm disruption

Often coinciding with irregular sleep times, exposure to light at night can shift your internal body clock, making sleep less efficient and mistimed, according to Dr Noussair.

“Stick to a regular sleep-wake schedule, limit blue light exposure at night, and get morning sunlight to reset your rhythm,” he adds.

6. Sleep apnea

Per Dr Noussair, sleep apnea is a condition that causes breathing to stop temporarily during sleep, forcing micro-awakenings (even if you’re unaware of them) that consequently interrupt deep sleep, potentially leaving a person fatigued the next day.

There are different types of sleep apnea with varying symptoms, and it’s not something anyone can or should try to diagnose themselves. If you want to determine whether sleep apnea might be impacting your sleep and energy levels, it’s highly advised that you speak to your health professional.

“See a doctor for a sleep study. Treatment may include a CPAP machine, weight loss, or sleeping on your side,” says Dr. Noussair.

7. Depression

Hypersomnia or hypersomnolence (excessive daytime fatigue despite sleeping enough) can be one of the symptoms of depression, with a reported 25% of patients said to experience it.

“Depression alters sleep architecture, often reducing time spent in deep sleep and causing early awakenings or oversleeping,” Dr. Noussair explains.

“Seek support from a mental health professional. Consider therapy, exercise, and possibly medication that can help regulate sleep.”

8. Chronic Fatigue Syndrome and other medical conditions

Unfortunately, some chronic health conditions not only impact our energy levels upon waking but can leave us feeling exhausted all the time.

“Conditions like Chronic Fatigue Syndrome (CFS), fibromyalgia, or hypothyroidism can leave the body feeling drained regardless of sleep quality,” says Dr Noussair.

As the symptoms and severity of these conditions can vary from person to person, it’s strongly recommended to speak to your doctor for individualised health advice.

“Consult a healthcare provider for diagnosis and treatment. Symptom management and tailored sleep strategies are key,” he adds.

How to improve your overall sleep and avoid waking up tired

Both before and after ruling out any underlying health concerns, there are a few things we can do to improve the sleep we are getting and reduce the amount of tiredness we experience the next day.

“Start by creating a consistent sleep routine, limit screens before bed, keep your bedroom cool and dark, and address stress or medical issues early – these small changes can significantly improve sleep quality,” says Dr Noussair.

This article is intended for informational purposes only and is not a substitute for individualised health advice. If you are concerned about your sleep, mental health or general wellbeing, please speak to your GP, who will advise you on the correct treatment plan. You can also call Mind for mental health support on 0300 102 1234 (9am to 6pm) or CALM on 0800 58 58 58 (5pm to midnight).