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I wake up at night shaking with my heart racing…

In the last 6 months I have realised that after 1 or 2 hours of sleep I wake up shaking and my hearts beats very fast. My body really trembles and I also feel a little bit nauseous. I am 28 years old, I eat very healthily and I exercise 5 to 7 times per week. I eat 3 main meals and 2 snacks every day – my last meal is around 5:30pm. Could my symptoms be hypoglycemia or panic attacks? I was also diagnosed with health anxiety.

1 March 2021

There are a number of reasons that we may wake up feeling shaky and experiencing trembling, and whilst this can be quite alarming, it is often not due to any emergency cause. The most common reasons that we may experience shaking are due to low blood sugar levels and anxiety, as you have mentioned. As it can be difficult to understand the cause without a full examination, and because these symptoms could potentially be a warning sign of an underlying condition, it would be sensible to get in touch with your GP for an assessment.

Below we will discuss some of the more common causes:

1) Hypoglycaemia

Hypoglycaemia is the name for when our blood sugars drop too low below 'normal' levels. The normal blood sugar in someone that does not have diabetes is between 4.0-5.9 mmol/L before meals and under 7.8mmol/L after meals (NICE,2015). Hypoglycaemia is much more likely to affect someone who has diabetes, but it is possible for it to be experienced if you don't.

Symptoms of hypoglycaemia that someone might experience include (, 2021):

  • shaking
  • tachycardia (fast heartbeat) and palpitations
  • dizziness
  • anxiety
  • confusion
  • paleness
  • sweating
  • blurred vision
  • headache
  • tiredness and irritability
  • extreme hunger.

Hypoglycaemia can occur overnight as well as during the day; and you may not be able to recognise some of the symptoms if this happens when you are asleep. 

Hypoglycaemia can occur predominantly due to: not eating enough or not eating for a prolonged period of time, drinking excess alcohol, large amounts of exercise or, if you have diabetes, having too high a dose of medication e.g insulin in relation to your sugar levels (Diabetes UK, 2021).

You mention that you exercise quite frequently and have your last meal at 5.30pm so it may be that you would benefit from a snack later on in the evening to see if this resolves some of your symptoms?

2) Anxiety and panic attacks

We can feel the effects of anxiety, even when we are sleeping; this could be characterised by frequent waking in the night or nightmares for example. Anxiety can be experienced with many of the same symptoms as with low blood sugar, and of which you are experiencing (MIND, 2021):

  • feeling uneasy
  • lightheaded or dizziness
  • sweating
  • fast heart rate or palpitations
  • faster breathing
  • shaking
  • pins and needles
  • feeling restless
  • nausea.

We can also experience panic attacks, which are our body reacting to, sometimes an unknown, fear or 'danger' in an exaggerated way. Panic attacks can feel extremely scary and we may even think that we are having a heart attack or going to die; but although upsetting, they do not pose a risk to immediate health (NHS, 2021).

As you say that you have been diagnosed with an anxiety disorder it may be that anxiety is the cause of your symptoms; it would be sensible to discuss this with your GP for a further assessment and guidance on how to best manage this.

3) Medication side effects

Certain medications can have a side effects of shaking, or palpitations, if you have recently started any new medications or changed any medication dose then you may need a medication review from your pharmacist or GP. 

If you were taking any medications to treat diabetes that could put you at risk of low blood sugar; including insulin, sulphonylureas and glinides, and you are experiencing symptoms of hypoglycaemia frequently then it is best to get in touch with your GP or diabetic specialist nurse to review how your blood sugar is managed (Diabetes UK, 2021).

There are certain other conditions that could cause a 'tremor', heart rhythm irregularities or muscle twitches including neurological disorders and electrolyte imbalances. Usually we would not expect to see such a common 'pattern' in your symptoms if this was the case, but this may be something that your GP wants to further investigate.

Answered by the Health at Hand nurses  

Sources and further reading

Other useful resources

Panic Disorder – NHS factsheet

Hypoglycaemia – NHS factsheet

References, 2021. High and low blood sugar symptoms. (Accessed: 25 Feb 2021)

Diabetes UK, 2021. What is a hypo? (Accessed: 25 Feb 2021)

Diabetes UK, 2021. Tablets and medications. (Accessed: 25 Feb 2021)

MIND, 2021. What is a panic attack? Available at: . (Accessed: 25 Feb, 2021)

NHS 2021. Get help with anxiety, fear or panic. (Accessed: 25 Feb, 2021).

NICE, 2015. Blood glucose and target levels. Available at:. (Accessed: 25 Feb 2021)

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