If you’re taking lithium, it’s important to have regular blood tests to check the level of lithium in your blood is in the right range. This is because if the level is too low, the medication won’t be effective, and if the level is too high you are at risk of getting some unhelpful side effects.

The NICE guidelines, which all healthcare professionals in England and Wales follow, recommends that anyone taking lithium has a blood test every three to six months, but with the current global shortage of test tubes it’s possible that your regular blood test may be delayed. This isn’t necessarily anything to worry about. Just keep taking your regular dose of lithium as prescribed.

However, if you are taking lithium and you haven’t had a blood test for more than six months, Professor Allan Young from the Centre for Affective Disorders at King’s College London, says you need to contact your healthcare professional and ask for a blood test as soon as possible if:

• your mood isn’t stable – your lithium level may be too low, which can lead to problems with your kidneys and other organs
• you’re experiencing severe nausea and vomiting, severe hand tremors, confusion, blurred vision and/or unsteady balance - these are all signs that your lithium level may be too high.

Never stop taking lithium suddenly or change your dose without speaking to your doctor first. If you stop taking it suddenly you could become unwell very quickly.

There’s more information about taking lithium here