There are few things in this world more annoying than not being able to fall asleep. Tossing and turning for hours on end is enough to leave anyone feeling frustrated, especially when there’s no obvious rhyme or reason for it. And when that happens, it’s easy to start believing the key to a better night is investing in expensive sleep tech or following a complicated 14-step ‘sleepy girl’ bedtime routine.

But there could be a simple explanation: low iron levels. While low iron – also known as iron deficiency anaemia – is commonly associated with symptoms such as tiredness, low energy and pale skin, it has also been linked to poor sleep. And with the National Institute for Health and Care Excellence (NICE) estimating that 8% of women in the UK have anaemia – a number that rises to 12% in pre-menopausal women due to blood loss during menstruation and pregnancy – this could be a bigger problem than we realise.  

While experts have long suggested that low iron levels can impact sleep quality – with studies showing a clear link between the two – it’s worth noting that no study has shown a direct causal relationship (ie one that shows one directly impacts the other).

However, there are many theories as to why those with anaemia seem to experience sleep issues. One of the main ones involves the role iron plays in dopamine production, explains Dr Suzanne Wylie, GP and medical adviser for IQ Doctor.

“Iron is essential for the production of dopamine, a neurotransmitter that helps to regulate movement and mood,” she explains. “Low dopamine levels can contribute to conditions such as restless leg syndrome (RLS), which causes uncomfortable sensations in the legs, which are often worse at night.”  

Low dopamine levels can also lead to a disruption in the sleep-wake cycle, making it harder for you to fall asleep and wake up.

Iron also plays a role in the delivery of oxygen around the body because it’s a key component of haemoglobin – a protein found in red blood cells that carries out oxygen transport. In this way, low iron levels can lead to tissues around the body – including the brain – getting insufficient oxygen, potentially leading to poor sleep quality and fatigue. 

The best way to tell if iron deficiency anaemia could be impacting your sleep is to speak to your GP. They can order a full blood count (FBC) test, which will tell you whether the number of red blood cells you have is normal; low levels indicate iron deficiency. If the cause of your deficiency isn’t clear (eg heavy periods), they might order more tests.

A good way to tell whether you should push for an iron test is by keeping an eye out for other symptoms of anaemia. While tiredness, a lack of energy, shortness of breath, heart palpitations, paler-than-usual skin and headaches are the most reported symptoms, others include tinnitus, hair loss and indented nails. 

Once you’ve got a diagnosis, you’ll usually be prescribed iron tablets. In the meantime, you can also try upping your intake of iron-rich foods (dark green leafy vegetables, dried fruit, pulses and fortified breads and cereals are all good options) and limiting your intake of foods that can disrupt the absorption of iron, such as tea, coffee, milk, dairy and foods high in phytic acid (such as wholegrain cereals) to see if it makes a difference. However, if you have concerns about your iron levels, your best bet is to get a diagnosis and then act on your doctor’s advice.     

Images: Getty