POTS and Insomnia: Why You're Wired but Tired and Can't Sleep

The exhaustion that will not let you sleep

Few things about POTS are as quietly demoralising as this: you are too tired to think straight, your body is begging to lie down, and then the moment you do, your heart picks up, your mind switches on, and sleep slips further away. POTS insomnia, the classic “wired but tired” night, is one of the most commonly reported symptoms in POTS, long COVID and related dysautonomia, and it rarely gets the attention it deserves. It is not a character flaw or bad sleep hygiene. It is your autonomic nervous system stuck in the wrong gear at exactly the moment it should be shifting down.

This article explains why the wired-but-tired feeling happens, what the overnight numbers (heart rate and HRV) actually show, and a calm, practical plan to settle the night. It is educational field notes, not medical advice, so treat it as a way to understand and track your own pattern, and bring any changes to a clinician who knows your case.

Why am I wired but tired?

Your nervous system runs on two branches that trade off through the day. The sympathetic branch is the accelerator: alertness, a faster heart, mobilised energy. The parasympathetic branch, carried mostly by the vagus nerve, is the brake: slowing, digesting, repairing. A healthy night is a smooth handover, accelerator easing off, brake taking over, so the heart slows and the body powers down.

In POTS and dysautonomia that handover is sticky. The system already sits with a sympathetic bias during the day, which is part of why standing makes the heart race. At night, instead of releasing the accelerator, it tends to keep a foot on it. So you get the paradox that defines the condition: a body that is genuinely depleted and an alarm system that will not turn off. Depleted plus alarmed equals wired but tired.

The physiology of a nervous system that will not switch off

Several threads tend to braid together. You will not have all of them, and naming the ones you recognise is the first step to loosening them.

Adrenaline surges when you lie down

This is the one that frightens people most. During the day, gravity pulls blood into your legs and abdomen, and your body fights to keep enough reaching your brain. When you lie flat, all of that pooled blood suddenly returns to your chest. In many people with POTS, especially the hyperadrenergic pattern, that shift triggers a release of adrenaline and noradrenaline rather than calm, so the heart speeds up and you feel a jolt of alertness just as you are trying to drift off. It is almost always distressing rather than dangerous, but it is real physiology, not anxiety inventing a problem. If the surges are severe, your clinician may discuss whether a medication that blunts that drive is appropriate, which is the territory of drugs like clonidine and guanfacine.

Stress hormones at the wrong time

Cortisol is meant to bottom out around midnight and climb toward morning to wake you. When the stress-response system is dysregulated, as it often is in chronic illness, that rhythm can flatten or shift, leaving you with more alerting hormone on board at night than you should have. The result is a mind that races at bedtime and an unrefreshing, broken sleep. HRV tracks this stress axis closely, which is why morning readings often sag after a run of poor nights. We go deeper in cortisol and HRV.

A heart that barely slows overnight

In healthy sleep, heart rate and blood pressure dip meaningfully overnight as the parasympathetic brake takes over. When the autonomic system is activated, that dip shrinks: the heart stays higher and flatter all night, sometimes with bursts of nocturnal tachycardia that wake you. A shallow overnight dip is not a diagnosis by itself, but it is a readable sign that your nervous system did not fully stand down, and it is one of the clearest things a simple overnight heart-rate trace will show you. See overnight heart rate for how to read the sleeping low and high.

Histamine and MCAS

Histamine is a wake-promoting chemical, which is exactly why old antihistamines make you drowsy. Many people with POTS also have mast cell activation, and a histamine surge in the evening or small hours can jolt you awake, sometimes with flushing, itching or a racing heart. If your worst nights cluster with other mast cell symptoms, that overlap is worth noting in your log.

The crash-and-rebound loop

Overdo it during the day and the body often answers with a wired, over-alert evening, the nervous system compensating for a stressed system by flooding it with more sympathetic drive. Then a bad night deepens the next day’s fatigue, which makes pacing harder, which worsens the next night. Breaking that loop is less about bedtime tricks and more about protecting your energy envelope across the whole day.

What is keeping you awake? A quick map

This is a map for your own tracking, not a diagnosis. The same night can have more than one driver, and the point is to spot which threads are yours.

How much does your heart slow at night?

One of the simplest windows onto nighttime autonomic recovery is the overnight heart-rate dip: how far your sleeping low falls below your daytime resting rate. A deep dip suggests the parasympathetic brake engaged well; a flat night suggests it did not. Try your own numbers, using a daytime seated resting rate and your lowest overnight heart rate from any wearable:

This is a wellness gauge, not a clinical test. The numbers vary a lot person to person and night to night, so read the direction over a couple of weeks rather than any single reading. A consistently shallow dip is a nudge to prioritise recovery and, if you snore or wake gasping, to get screened for sleep apnea, which both flattens the dip and keeps the nervous system on edge. More on that link in sleep apnea and HRV.

What actually helps

The honest headline is that the strongest lever is not a bedtime trick: it is lowering overall sympathetic drive, through the day as much as at night. Still, the evening matters, and small changes stack. Think of it as a gradual descent rather than a switch.

Through the day

• Pace to protect the evening. The single biggest cause of a wired night is often an overcooked day. Spreading effort and resting before you are forced to protects against the adrenaline rebound. The pacing guide covers how.
• Get morning daylight. Light within an hour of waking anchors your body clock and strengthens the night-time dip in alerting hormones. Even a few minutes near a bright window helps.
• Keep a consistent wake time. This is the highest-yield habit in all of sleep, and it holds doubly here. Anchor the morning even after a rough night, and let the body clock do the rest; chasing lost sleep with a late lie-in usually backfires.
• Time fluids and salt earlier. Keeping salt and fluids up supports blood volume, but front-loading them earlier in the day reduces the 2 am bathroom trip and the dizzy, wide-awake stand that follows.

In the evening

• Dim the lights an hour or more before bed and get off bright screens, which suppress the sleep signal and keep the accelerator pressed.
• Avoid late caffeine, alcohol and big meals. Alcohol in particular fragments sleep and blunts overnight recovery, even when it helps you fall asleep. Large late meals pull blood to the gut and can worsen symptoms.
• Keep it cool and dark. Heat intolerance is common in POTS, and a warm room makes settling harder. A cooler bedroom genuinely helps.
• Breathe slowly. A few minutes of paced breathing at roughly six breaths a minute nudges the vagus nerve and shifts you toward the parasympathetic side. This is the same mechanism behind resonant breathing, and it is one of the few things that reliably lowers the alert signal on demand.

Your bed and body

• Raise the head of the bed. Sleeping with the head slightly elevated reduces overnight fluid shifts and nocturnal urine production for some people, which can mean fewer wakeups. See head-up tilt sleeping.
• Legs up earlier, not at bedtime. Elevating your legs in the evening helps mobilise pooled blood gently, rather than all at once when you lie down.
• Consider magnesium, with care. Some people find a magnesium supplement helps sleep and symptoms; the evidence is modest and it is not for everyone, so read magnesium for HRV and POTS and check with your clinician first.

Habits that help versus hinder

When to talk to a clinician

Most wired-but-tired nights are a tracking-and-habits problem, but a few things deserve a professional eye. Raise them if they fit you:

• Loud snoring, gasping, witnessed pauses, or unrefreshing sleep despite enough hours. These point toward sleep apnea and warrant a sleep study.
• New, severe, or sustained palpitations at night, chest pain, or fainting. Nighttime adrenaline surges are usually benign, but new or dramatic symptoms should be evaluated.
• Insomnia that persists for weeks and wrecks your days. There are effective, non-drug treatments (such as cognitive behavioural therapy for insomnia) and your clinician can tailor an approach, including whether any medication fits your autonomic picture.
• Night sweats, significant weight change, or a racing heart during the day too, which can point to thyroid or other issues worth checking.

None of this is a reason to panic. It is a reason to bring good information to the person who can act on it.

Track the pattern instead of fearing it

The cruelty of a wired-but-tired night is partly that it feels random and frightening. The antidote is making it visible. When you can see that last night’s heart barely dipped, that your morning HRV sags after busy days, and that your best nights follow well-paced ones, the symptom stops being a mystery and becomes a signal you can work with.

The bottom line

The wired-but-tired night is not you failing at sleep. It is a nervous system leaning on its accelerator when it should be reaching for the brake, made worse by fluid shifts on lying down, mistimed stress hormones and a heart that does not fully stand down overnight. The way out is to lower that drive, patiently and across the whole day: pace so the evening is not a rebound, catch the morning light, keep the room cool and dark, breathe slowly before bed, and hold a steady wake time even after a bad night. Track your overnight heart rate and morning HRV so the pattern becomes readable, rule out sleep apnea, and work changes through with a clinician. Night by night, a frightening symptom becomes a map of your recovery.