It's long been thought of as a toxic emotion and now a new study suggests that an explosion of anger can, in some cases, trigger a stroke.
The global study, co-led by National University of Ireland (NUI) Galway, found that one in 11 stroke survivors had experienced a period of anger or upset in the hour leading up to it.
The large-scale research, published in the European Heart Journal this week, looked at 13,462 cases of acute stroke, involving patients with a range of ethnic backgrounds in 32 countries.
It's no surprise that anger and upset can have this effect, say experts: when we're livid or devastated these feelings trigger the fight or flight response, stress hormones skyrocket, while heart rate and blood pressure soar.
"Anger can lead to heart rate increases and blood pressure," confirms Andrew Smyth, professor of clinical epidemiology at NUI Galway, who was one of the lead researchers on the study.
"And you may also at the same time, get some hormones that cause some tightening of the blood vessels in the brain in particular. And those two things together can lead to a rupture of a blood vessel, as in a haemorrhagic stroke, with bleeding in the brain.
"The other thing that can happen, in ischemic type strokes, which are more common, is that there's either a plaque or an existing narrowing in a blood vessel leading to the brain – as we see in heart disease – where the changes in pressure and the changes in flow in the blood vessel make the area of the brain vulnerable."
And stroke is a serious concern. A leading global cause of death or disability, one in six people will have a stroke in their lifetime and 100,000 people suffer from stroke each year. There are 1.3 million stroke survivors in the UK, says the Stroke Association.
However, aren't we often told that expressing our anger is healthy?
The worst thing you can do is bottle your temper up, warns founder of the British Association of Anger Management, psychotherapist Michael Fisher, creating internal "quiet rage".
"In the UK," says Fisher, "we're a culture of imploders. We keep it in but we're still releasing stress hormones, which break down the immune system and all sorts of physical symptoms can emerge."
An angry outburst, or short-term stress (fight or flight) might trigger a dry mouth, racing heart and digestive issues, and could leave us feeling sweaty or light-headed.
But pent-up anger, say from a boss who riles you on a daily basis, or a toxic relationship, could result in large amounts of free floating cortisol, triggering an increased appetite and – eventually – metabolic syndrome, with added belly fat, increased blood pressure and abnormal cholesterol or triglyceride levels.
So how do we reduce our risk from a toxic temper or, just as dangerous, that quiet rage? Apparently, the secret lies in the strength of our feelings.
"It's actually healthy to express anger," says Richard Stephenson, an anger management specialist and psychotherapist at Nightingale Hospital, London. "It's rage that's the bad thing; if you don't say anything, but you sit there and brood."
When anger erupts in an uncontrolled outburst or is repressed in seething quiet rage, that's when it's potentially dangerous to our overall health and wellbeing. So how do we manage it?
"We all need to find coping strategies, to help us deal with angry episodes or upsetting circumstances," says Smyth. "Things will happen that trigger our body's response and how we can adapt to that is critical. I think it's really important that people find what works for them, whether that's breathing exercises, meditation or techniques from mindfulness."
Controlled deep breathing has been shown to slow the heart rate, in a way that's as effective as benzodiazepine sedatives. And while numerous studies have shown us that exercise can improve your mood, beware stepping up your activity levels too quickly, says Smyth, as the NUI study found that stroke was also linked to heavy exertion.
Try concisely changing your approach to whatever made you angry in the first place, suggests Stephenson. "You can say, 'That upset me, you've let me down'.
"Be aware of your triggers and your thought processes. Most of the time when things escalate, it's because no one will back down. It's the ego or an historical thing that's causing that reaction. You can start to recognise, 'people that talk to me like that, it brings up this in me'."
Often anger is a secondary emotion, adds Stephenson. "Behind the anger you've got sadness, fear, resentment, pain, and because people can't express their emotions, it comes out as anger. When people are rageful there's usually something that's happened in their history."
So work out what lies behind your feelings of temper and look to solve that first; your heart, head and blood pressure will thank you for it.