Why you can’ sleep despite feeling exhausted: your thyroid might be to blame
Do you constantly feel tired—even after getting plenty of sleep? Or do you lie awake at night even though your body is completely drained? Your thyroid could be playing a major role in all this. The link between thyroid health and sleep disorders is stronger than most people realize.

The good news? Once you understand the root cause, you can take targeted steps to finally get the deep, restful sleep you’ve been missing.

In this article, you’ll learn:

• How your thyroid affects your sleep-wake cycle
• Why an underactive thyroid leads to restless sleep
• How an overactive thyroid can cause trouble falling asleep
• What Hashimoto’s thyroiditis has to do with your sleep issues
• Whether taking thyroid meds at night can disturb your sleep
• How melatonin and thyroid hormones work together
• Practical tips for better sleep with thyroid Problems
• Answers to the most frequently asked questions on this topic

The thyroid hormones triiodothyronine (T3) and thyroxine (T4) are molecular messengers that travel through the bloodstream to every cell in your body. These hormones not only regulate your metabolism but also directly influence the production of melatonin in the pineal gland of your brain [2].

Melatonin is your body’s primary sleep hormone and controls your natural circadian rhythm—your internal biological clock that tells you when to feel tired and when to sleep.

When your thyroid becomes dysfunctional and develops hypothyroidism or hyperthyroidism, it creates a hormonal imbalance that disrupts your neuroendocrine system [3].

Simply put: the finely tuned interaction between thyroid hormones and sleep hormones gets thrown off balance. Your internal clock falls out of sync, and the natural signals for tiredness and alertness either show up at the wrong times—or don’t show up at all.

Your nighttime sleep is like a choreographed performance made up of several acts. Normally, you cycle through multiple 90-minute sleep phases that include light sleep, deep sleep, and REM sleep (the dream stage).

Thyroid hormones T3 and T4 act like directors of this nighttime performance [4]. They influence the length and depth of each sleep stage. When your thyroid is functioning properly, these phases alternate in a smooth, balanced rhythm—allowing you to wake up refreshed.

Deep sleep is especially important for your physical recovery. During this stage, your body repairs itself, the immune system is strengthened, and growth hormones are released. Thyroid hormones help regulate these processes by coordinating your metabolism even while you sleep [5].

REM sleep, on the other hand, is critical for mental recovery, memory formation, and emotional processing. Thyroid hormones help regulate the neurotransmitters responsible for dreaming and mental regeneration [6].

When your thyroid isn’t working properly, this finely tuned sequence is disrupted. Your sleep phases may become shorter, longer, or less intense. The result? You’re technically sleeping, but your body and mind aren’t truly recovering.

The effect of melatonin on the thyroid is a fascinating area of research. Melatonin—our body’s natural sleep hormone—and thyroid hormones work together to regulate melatonin production in the brain’s pineal gland.

In cases of hypothyroidism, melatonin production may be disrupted, which helps explain why many people with underactive thyroids have trouble falling asleep [15]. In contrast, with hyperthyroidism, melatonin levels can be too low, often leading to insomnia.

Interestingly, melatonin itself has antioxidant properties and may help protect the thyroid from damage. Some studies even suggest that melatonin could have anti-inflammatory effects in people with Hashimoto’s thyroiditis [16].

With an underactive thyroid (hypothyroidism), your metabolism runs like a car engine idling in neutral. You might think this would lead to more rest and better sleep—but the opposite is true [4].

Your body may feel tired, but it’s the kind of exhaustion that hangs over everything like a heavy curtain—without offering real recovery.

Many people with hypothyroidism describe their sleep as restless and unrefreshing [5]. They wake up in the morning feeling like they’ve worked all night, even after spending eight or nine hours in bed. The reason lies in disrupted sleep cycles: your body struggles to reach the deep sleep stages that are essential for both physical and mental recovery.

An overactive thyroid (hyperthyroidism) is like an engine stuck on full throttle. Your body is in a constant state of alert—almost as if it’s preparing for a danger that never arrives [7]. In this state, truly restful sleep becomes nearly impossible.

The excess thyroid hormones act like a never-ending dose of strong coffee. Your heart races, your thoughts spin, and your body feels like it’s buzzing with electricity [8]. Falling asleep becomes a challenge because your nervous system just won’t calm down.

Even if you do manage to fall asleep, your rest is often light and broken up by frequent awakenings [9]. It’s as if your body stays on guard, snapping awake at the slightest noise or movement.

The comparison between hyperthyroidism (overactive thyroid) and hypothyroidism (underactive thyroid) when it comes to sleep reveals some striking contrasts.

With hypothyroidism, it’s as if your body is moving in slow motion. You feel sluggish and tired, but the sleep you get isn’t truly restorative. It’s like a computer running in power-saving mode—it’s still functioning, just at a much slower pace.

With hyperthyroidism, your body runs like an engine in overdrive. Sweating and sleep problems related to the thyroid often go hand in hand. You lie awake at night, your heart racing, sweating, and your mind spinning. It’s as if someone is constantly pumping caffeine into your system.

People with hypothyroidism often sleep a lot but wake up feeling unrefreshed, while those with hyperthyroidism often struggle to fall asleep at all. Yet both extremes lead to the same result: you feel exhausted and unrested during the day [13].

Hashimoto sleep disorders have a unique dynamic. With this autoimmune condition, your immune system attacks your own thyroid, leading to fluctuating hormone levels [10]. These fluctuations feel like a constant rollercoaster, making your sleep especially unpredictable.

People with Hashimoto’s often describe periods of poor sleep that last for weeks, followed by short stretches of better rest. This unpredictability makes it hard to establish a stable sleep routine. On top of that, inflammation in the body can further disrupt sleep quality [11].

A common question is whether taking thyroid meds at night can cause sleep problems. The answer is nuanced.

Generally, thyroid meds are taken in the morning on an empty stomach, as this allows for optimal absorption. However, some people choose to take them in the evening—for convenience or because they’re taking other medications in the morning.

Thyroid meds are synthetic hormones that deliver energy to your body slowly and steadily. They don’t act like caffeine, which gives you a quick jolt. That said, some people are more sensitive—especially if the dose is too high or their body is still adjusting to the medication [14].

If you’re taking your thyroid meds at night and experiencing sleep issues, there could be several reasons:

• Your dosage might be too high, causing mild symptoms of overactivity
• Your body may need more time to adapt to the hormonal shift

In any case, talk to your doctor before making any changes to your dosing schedule.

Not every bad night or tired phase points directly to a thyroid problem. However, certain combinations of symptoms act like red flags and may indicate a possible thyroid disorder.

Classic warning signs of hypothyroidism:
You should pay attention if, along with sleep issues, you also experience the following:

• Unexplained weight gain despite normal eating habits
• Constantly feeling cold (even when others are warm)
• Dry skin and brittle hair
• Constipation
• Slowed heart rate
• A sense of heaviness or lack of motivation [18]

Warning signs of hyperthyroidism:
These symptoms tend to look quite different:

• Unintentional weight loss despite having a healthy appetite
• Excessive sweating
• Rapid or irregular heartbeat
• Inner restlessness and nervousness
• Diarrhea
• Shaky hands
• Unusual sensitivity to heat [19]

Pay close attention if:

• Your sleep problems persist for several weeks or months and don’t improve despite good sleep hygiene
• You wake up feeling like you haven’t slept at all, even though you spent enough time in bed
• Your sleep issues are paired with other physical changes you can’t explain

Another important red flag is if close family members have thyroid issues. Thyroid conditions—especially Hashimoto’s thyroiditis—often run in families [20]. If your parents, siblings, or grandparents have been affected, you should be especially alert to any symptoms.

The right time to see a doctor:
In general, it’s better to go a little too early than too late. A simple blood test can provide clarity and takes only a few minutes. The most important values to check are TSH (thyroid-stimulating hormone), fT3, and fT4. If Hashimoto’s is suspected, antibody levels will also be tested.

The connection between thyroid health and sleep disorders is complex—but definitely treatable. Whether it’s hypothyroidism, hyperthyroidism, Hashimoto’s, or another thyroid issue, the first step toward improvement is always getting the right diagnosis and treatment for your thyroid levels.

It’s important to understand that sleep problems related to thyroid disorders are not “just in your head.” They have a real physical cause that can be addressed medically. With the right thyroid treatment, sleep issues often improve significantly.

In addition to medical treatment, good sleep hygiene, relaxation techniques, and patience can support your healing process. Your body needs time to adjust to new hormone levels—but with the right treatment, you can return to restful nights.

The good news is that many sleep-related problems improve once your thyroid levels are back in balance [13]. It’s important to work with your doctor to find the right medication. Sometimes it takes a bit of patience, as your body may need time to adapt.

Alongside medical care, you can support your sleep by practicing healthy sleep habits [14]. Your bedroom should be like a cave: cool, dark, and quiet. Try to avoid bright screens in the evening, as the blue light can interfere with your melatonin production.

Relaxation techniques can also help [15]. Meditation, progressive muscle relaxation, or deep breathing exercises serve as a gentle transition from day to night. They send your body a clear signal: it’s time to wind down.

What you eat and drink can have a direct impact on your melatonin production—and therefore your sleep. Especially when dealing with thyroid issues, it’s important to support your body with the right nutrients.

Melatonin-boosting foods: Certain foods either contain natural melatonin or help your body produce more of it. Tart cherries are true melatonin powerhouses and can be consumed as juice or dried fruit about an hour before bedtime [21]. Walnuts, almonds, and oats also support natural melatonin production. Bananas provide tryptophan, an amino acid your body needs to produce melatonin.

Key micronutrients:
Magnesium acts like a natural calming agent for your nervous system and can be especially helpful for those with hypothyroidism, where deficiencies are common [22]. Zinc and selenium are not only essential for proper thyroid function but also support healthy sleep. Vitamin D plays a role in regulating the sleep-wake cycle and is often found to be low in people with thyroid issues.

Helpful supplements:
Melatonin as a supplement can help in the short term but should only be taken after consulting with your doctor. Doses vary greatly between individuals—often just 0.5 to 1 mg is enough [23]. Magnesium (200–400 mg in the evening), L-theanine from green tea (100–200 mg), and glycine (1–3 g) can also naturally improve sleep quality without causing dependency.

What to avoid:
Try to avoid caffeine after 2 p.m., as it can stay in your system for up to 8 hours. Alcohol may make you sleepy at first, but it disrupts the important REM sleep phases. Heavy, fatty meals in the evening can overload your digestive system and negatively impact your sleep.

Remember that your body is a complex system where everything is connected. Your thyroid is just one part of that system—but a very important one. When it falls out of balance, your entire body feels it—especially your sleep.

With the right treatment and a bit of patience, you can find your way back to restful nights. Your body has an incredible ability to heal and adapt. Give it the time and support it needs, and you’ll be able to enjoy the kind of sleep you truly deserve.

Yes, the thyroid directly affects your sleep-wake cycle and the production of sleep hormones like melatonin. both overactive and underactive thyroid function can lead to various sleep issues.

With hypothyroidism, your sleep architecture is disrupted, and you don’t reach the deep sleep stages your body needs. as a result, your sleep isn’t truly restorative—even if you spend plenty of time in bed.

Thyroid meds themselves usually don’t cause direct sleep problems, since they work slowly. issues typically arise from an overly high dose or during the adjustment phase as your body gets used to the new medication.

Melatonin can be helpful, but it should only be taken after consulting with your doctor. with thyroid issues, your body’s natural melatonin production is often disrupted, so supplementation might make sense in some cases.

Sleep improvement can take anywhere from a few weeks to a few months, as your body needs time to adjust to the new hormone levels. patience is key—thyroid treatment takes time to fully take effect.