Taking blood pressure tablets is something we usually associate with older people, but Daniel Radcliffe has openly spoken about taking the medication at the age of 25.
The actor has said he takes blood pressure medication to control his cluster headaches - a neurological disorder which causes severe headaches on one side of the head.
Speaking to The Guardian, Daniel said: "You have to be on blood pressure medication and have an ECG every so often."
Despite the surprising news of his ill health, the former Harry Potter star did reassure interviewer Tim Jonze that he was "perfectly fine".
Daniel first revealed he was suffering from cluster headaches in an interview with the Independent in 2012. At the time he said they were "exceptionally painful."
Cluster headaches are rarely reported on, so HuffPost UK Lifestyle spoke to Dr Guy Leschziner, Consultant Neurologist at The Lister Hospital, London, to find out more about the condition.
What are cluster headaches?
Cluster headache (CH) is a form of usually recurrent headache somewhat different to migraine.
Typically the headaches are extremely severe, and are often focused behind the eye. Unlike migraine, they usually recur several times a day, lasting from an hour up to several hours, and the pain is so severe that sufferers will try anything to get relief.
They are associated with other features such as reddening or tearing of the eye, or nasal dripping or congestion.
How does blood pressure medication help to relieve/ manage the symptoms?
Verapamil is a standard preventative treatment for CH, and seems one of the most effective drugs in the prevention of CH attacks. It is taken on a daily basis, in contrast to pain relief.
Why does blood pressure medication have an effect when paracetamol and other painkillers don't?
CH usually does not respond to standard painkillers, although sometimes improves with a class of drug called triptans. However, verapamil does not stop the headache once it starts, but attempts to get rid of the headaches in the long-term.
Are there any side effects/ disadvantages to using blood pressure medication to manage cluster headaches?
Obviously this drug can cause your blood pressure to drop, resulting in lightheadedness or dizziness.
Importantly, verapamil can block the conduction of impulses in the heart, causing your heart rate to slow to problematic rates, so when it is started or the dose is increased, an ECG is necessary to ensure that this is not happening.