• A single poor night’s sleep does not raise inflammation, but three or more nights of disrupted sleep does, measurably raising the inflammatory markers IL-6 and CRP in your blood.
• The relationship works both ways. Inflammation also disrupts sleep, which is why the cycle can feel hard to break.
• Your gut bacteria are involved. Poor sleep changes the balance of your microbiome and can increase intestinal permeability, adding fuel to systemic inflammation.
• Magnesium, omega-3 fats and tryptophan from food all support both sleep and calmer inflammation.
• Herbs such as valerian, passionflower and ashwagandha can help, but they work best when matched to what is actually driving your sleep problem.

Disrupted sleep raises inflammation. Not dramatically, and not after one rough night, but it happens, once poor sleep becomes a pattern. And, inflammation, in turn, makes sleep worse. Understanding this loop is the first step towards doing something about it.

Your immune system follows a daily rhythm which is tied to your sleep. During deep sleep, your body produces more of the signalling molecules called cytokines, particularly interleukin-6 (IL-6) and tumour necrosis factor alpha (TNF-alpha). These are part of normal immune housekeeping, a controlled burst of activity that prepares your defences for the day ahead.

When your sleep is cut short or broken, that timing falls apart. The cytokines that should peak during the night begin to spill into the daytime, producing a state of low-grade inflammation that your body was never designed to sustain around the clock.

A 2025 meta-analysis of 35 studies looked at what happens when healthy adults have their sleep experimentally reduced to around four and a half hours a night for three or more nights. Both IL-6 and C-reactive protein (CRP) rose significantly. But, a single night of poor sleep, whether total or partial, did not produce the same effect. The threshold appears to sit at around three consecutive nights of short sleep before the inflammatory response kicks in measurably.

That’s something worth being aware of, because it means one bad night is not a disaster. What matters is the pattern.

The pathway driving this is a molecule called NF-kB, which acts as a master switch for inflammatory gene expression. When NF-kB is activated in your immune cells, it turns on the genes that produce inflammatory cytokines. A study of 14 healthy adults found that a single night with partial sleep loss activated NF-kB significantly. And, in that study, the activation was found in women but not in men.

The relationship between sleep and inflammation acts in both directions. Poor sleep raises inflammation, and raised inflammation disrupts your sleep. A 2024 narrative review described this as a cycle in which each side drives the other, and a 2025 review noted that the inflammatory effects of sleep loss can persist even after one or two nights of recovery sleep.

This helps to explain why broken sleep can feel so hard to fix once it sets in. If inflammation is already elevated, whether from poor sleep, diet, stress, or something else, your sleep quality is likely to suffer as a result, which raises inflammation further.

More than 40 per cent of women going through perimenopause report sleep problems, and the reasons go deeper than hot flushes keeping you awake. Oestrogen and progesterone both play a role in sleep regulation. As levels of these hormones fall, the systems that control your body temperature, your circadian rhythm and your ability to stay asleep are all affected.

At the same time, the decline in oestrogen removes some of its protective effect against inflammation. Oestrogen helps to keep inflammatory signalling in check, so as levels drop, the same amount of sleep disruption may produce a stronger inflammatory response than it would have done ten years earlier.

This is part of why so many women over 45 notice that everything seems to come at the same time: broken sleep, joint stiffness, brain fog, low mood, weight that is harder to shift. These are not separate problems. They share a common thread of low-grade inflammation, and disrupted sleep is one of the things driving it.

Your gut bacteria follow their own daily rhythms, and these are closely tied to your sleep cycle. When sleep is disrupted, the balance of the microbiome can change. A study in mice found that chronic sleep disruption altered the composition of gut bacteria, increased intestinal permeability, and led to both systemic and fat tissue inflammation. A 2026 review of the human and animal evidence confirmed that sleep deprivation, circadian misalignment and intermittent low oxygen during sleep can all disrupt the gut barrier and alter microbial metabolites.

When your gut barrier becomes more permeable, bacterial products such as lipopolysaccharide (LPS) can cross into your bloodstream and activate those same inflammatory pathways that sleep loss triggers directly. So, your gut becomes another source of fuel for the cycle.

The gut connection also runs in the other direction. Your gut bacteria produce many of the precursor compounds your brain needs to make serotonin and melatonin, both of which are involved in regulating sleep. A gut that is out of balance may not produce enough of these precursors, making it harder to fall asleep and stay asleep. If your sleep is poor and your digestion is also unsettled, the two are probably not separate issues. There is more on this in my post on how serotonin affects gut health, mood and sleep.

Magnesium is involved in more than 300 processes in your body, including nervous system regulation and the production of melatonin. Low magnesium is common and often missed, because blood tests can look normal while tissue stores are depleted. Pumpkin seeds, spinach, almonds and dark chocolate are all rich sources. Magnesium bisglycinate is the form most often used to support sleep, but I think food is the place to start. There is a detailed post on magnesium forms and absorption if you want to go further.

Tryptophan is the amino acid your body uses to make serotonin, and from serotonin, melatonin. Good sources include eggs, chicken, oats, pumpkin seeds and cheese. Eating these alongside some carbohydrate in the evening can help tryptophan to cross the blood brain barrier more effectively.

Omega-3 fats from oily fish such as wild salmon, mackerel and sardines have well established anti-inflammatory effects, and some evidence links them to improved sleep quality as well. Two to three portions of oily fish a week is a reasonable target.

Fibre feeds the gut bacteria that produce short-chain fatty acids, which help to keep your gut lining intact and reduce intestinal permeability. Vegetables, pulses, oats, nuts and seeds all contribute. There is more on supporting your gut bacteria through food in my guide to improving gut health naturally.

Tart cherries, eaten whole or as juice, are one of the few food sources of melatonin. The evidence is still developing, but the existing trials suggest a modest benefit for sleep quality and duration.

Valerian is probably the best known. It works on the GABA system, the same calming neurotransmitter pathway that pharmaceutical sleep aids target, but much more gently. Trials suggest it can reduce the time it takes to fall asleep and improve overall sleep quality, particularly when taken consistently for two to four weeks. Around 10 per cent of people get a paradoxical stimulant response from using valerian, probably due to individual genetics.

Passionflower has a calming effect and some trial evidence for improving sleep quality, particularly where anxiety is part of the picture. It acts partly through apigenin, a compound that binds to receptors in your brain involved in relaxation.

Ashwagandha takes a different approach. Rather than sedating directly, it helps to lower cortisol, the stress hormone that can keep your nervous system running too high for sleep. If your problem is less about falling asleep and more about waking in the early hours with your mind already active, high cortisol may be part of what is going on. There is more on how ashwagandha works in the ashwagandha benefits post.

Lemon balm is gentle and calming, and there is some evidence that combining it with valerian produces a stronger effect on sleep quality than either herb alone. It is easy to use as a tea in the evening.

These are gentle plants that build their effects over time. If you take prescribed medication, it is worth checking with a medical herbalist who knows your case, because some herbs can affect the liver enzymes that clear medication.

This post on feeding your nervous system covers the nutritional side of calming the nervous system in more detail, and the nervine herbs post goes deeper into the calming plants.

A consistent sleep window matters more than the total number of hours. Going to bed and getting up at roughly the same time, even at weekends, keeps your circadian rhythm stable. Your gut bacteria have their own daily rhythms too, and a regular sleep pattern helps to keep those in step.

Morning light resets your internal clock. Ten to twenty minutes of natural light in the first hour after waking helps your brain to produce melatonin at the right time later in the day. On dark winter mornings, even a short walk makes a difference.

Eating earlier in the evening gives your digestive system time to wind down before sleep. A large meal close to bedtime raises your core temperature and this can fragment your sleep. Leaving two to three hours between your last main meal and bed is a practical target.

Calming your nervous system before bed does not need to be complicated. A warm drink, slow breathing, or a few minutes of stretching are enough. The point is to give your body a consistent signal that the day is ending. Box breathing, four counts in, four held, four out, four held, is one of the simplest techniques and it works quickly.

One bad night will not set off an inflammatory cascade. But a few weeks of broken sleep can, and if you are also going through hormonal changes, you may feel the effect worse than you may have done in your thirties. The encouraging part is that this can respond well to some simple habits I’ve mentioned here: getting consistent sleep, good food, the right herbs, and a calmer nervous system in the evening.