“Oh my God, I love a scream,” says Dr Jennifer Cox, her face lighting up. “Screaming underwater, I recommend. It’s amazing. It’s so liberating and no one can hear.”

The same is true for standing on a motorway bridge and venting your pent-up rage and frustration into the roar of the traffic underneath. Or, at a pinch, for yelling under the noise of the shower, she says. “Women are like: ‘Oh, I can’t be seen to do this stuff.’ OK, don’t be seen. But let it out.”

Sipping an earl grey tea in a London cafe, Cox doesn’t seem a woman with much to scream about. A Cambridge-educated and Tavistock Clinic-trained psychotherapist, she co-hosts (with the writer and actor Salima Saxton) the podcast Women Are Mad, and is just about to publish her first book, Women Are Angry: Why Your Rage is Hiding and How to Let it Out. Both are responses to something she kept noticing in female patients: a bottled-up, repressed anger that they were highly resistant to talking about.

We live in an age of rage, with anger at perceived political and social injustices spilling over endlessly on social media; in street protests such as the recent marches over Gaza; and lately into election debates. The book was inspired by Cox’s own anger at the murder of Sarah Everard by a serving police officer, which she says “started to crystallise to me all the things I’d been noticing and worrying about in my patients, and hearing about with friends and family, and feeling myself”. But her focus is less on this kind of publicly expressed anger than on an intimate, swallowed kind, seemingly often triggered by those her patients were closest to – from ageing parents to partners not doing their fair share at home.

Why does anger so often seem confusingly embroiled with love? “Maybe there’s a sense of hurt,” says Cox of the domestic point. “Like: ‘How can you, this person who was meant to love me, we were meant to be in it together – at what point did it come to pass that I would be the one expected to do this? That we wouldn’t be having conversations about it?’” It is, in other words, more personal than being furious about a war or a government’s failure to act on the climate crisis, where “you can empathise with what’s happening, and it’s awful – but it’s a very different set of feelings”.

Cox’s book is a feminist take on anger-inducing life experiences; from unresolved feelings about miscarriage and loss, to the sometimes maddening business of looking after toddlers, feeling undermined at work, partners failing to pull their weight at home, sexual harassment and violence. Her argument is essentially that it is hardly surprising many women are hopping mad and that their suppressed feelings eventually burst out, sometimes with toxic consequences. She is fascinated by the phenomenon of women becoming online trolls, venting spleen under the cover of anonymity. (“I think trolling is a horribly brilliant way of being able to enact that destruction, but invisibly,” she says.)

Cox previously worked in forensic psychology, mostly with violent male offenders. “I was used to sitting in their bucket-loads of rage, and often at the sharp end of it,” she says. What she had not expected was to find the same feelings in women at her private practice. “It’s obviously presented very differently: it’s all squashed away and they come in saying: ‘I’ve got migraines, I’ve got terrible irritable bowel syndrome, my anxiety is through the roof, I’m very depressed.’ But just scratch a little bit and that feeling comes out.”

Cox began wondering whether suppressed rage might be undermining women’s mental – and sometimes physical – health, and whether recognising and expressing it might help them move on faster. Cox stresses that she isn’t suggesting the diagnoses her clients arrived with, from panic attacks to chronic pain, aren’t real. Rather, she is arguing that a diagnosis isn’t always the whole story, and that for many women that story is complicated.

A BBC analysis of 10 years of data from the Gallup World Poll – which tracks issues such as food access, employment and wellbeing across the globe – found that, by 2021, women were angrier than men by a margin of six percentage points, with the gap widening during the pandemic. Women’s rage differs from men’s, Cox argues, because women are conditioned in a patriarchal society not to show it publicly (much as men are conditioned not to show sadness or fear). “Women have to stay in their place and be very nice, accepting and kind.”

Girls learn that crying is fine, but that yelling is unfeminine. Angry older women are caricatured as screeching harridans, while righteously angry younger ones are told they just can’t take a joke. Black women are portrayed as particularly aggressive if they lose their tempers. “Whatever way society has of squashing them, it does, and that angry black women trope is kind of classic,” says Cox. Meanwhile, angry white women can also be dismissed as “Karens”, stereotypically entitled middle-class whiners. Essentially, women learn that anger isn’t socially acceptable and that losing control means they won’t be taken seriously. “It’s really easily humiliating and shaming, isn’t it? We kind of embarrass ourselves,” Cox says. Easier, then, to keep a lid on it.

Women Are Angry is built around case studies, anonymised amalgams of multiple patients Cox has treated, and divided up by life stages, from childhood through to old age. Many new mothers who endure traumatic births, she writes, are left feeling angry and cheated. But those feelings are often brushed under the carpet, with women encouraged to be grateful that they emerged with a healthy baby. “This whole gratitude thing is a problem; it’s the enemy of good mental health. Of course there’s a place for it and, of course, attitudinally we feel better when we look at the positive. But so we can get there, we have to let ourselves discharge the negative.”

When that anger isn’t discharged, she says, it can resurface as shame, or feeling there must be something wrong with you. “What’s awful about that is that often it gets corroborated by others in that woman’s life – especially with things like bringing up young kids. So often, what I hear is the male partner comes home and says: ‘But my friends’ wives are fine!’ Then it’s like: ‘Not only am I doing this really badly, but there’s something wrong with me – I’m the odd one out.’ When you go to baby classes, they never really talk about how shit this is.”

Many new mothers will recognise the flashes of primal rage that can come with being chronically sleep-deprived, sore, and having your life turned upside down. But there are good biological reasons for women suppressing those feelings in early motherhood. Anger isn’t necessarily a safe emotion around a baby, I say. “No,” she concedes. But she points out the difference in telling someone close to you, in a matter-of-fact way, that you are struggling with these frightening feelings of rage and that person saying they understand, compared with: “Oh my God, let’s get you to a GP, to mental health services. I’m scared by you saying this.”

The more histrionic response, she says, “creates a different kind of dialogue around something that is actually ordinary and understandable, and it would be weird if you didn’t feel that”. What needs to be normalised isn’t lashing out, but openly acknowledging anger, so that you can focus on trying to fix whatever is fraying your temper.

Stressed women are often encouraged to self-soothe by running a hot bath or lighting a candle, strategies that exasperate Cox. “It makes me feel really furious even as you describe those activities. Like, fine – but get the anger out first and then do your lovely thing. Reward yourself for having been brave enough to get it out.”

But how you expunge those emotions can be crucial, especially if the person you’re furious with is the boss who has been sidelining you since you took maternity leave. “It isn’t just about losing the plot in the middle of a meeting because nobody’s listening,” Cox says. Which is where underwater screaming can come in.

For those who can’t face howling into the depths of the nearest municipal pool, Cox has other suggestions. Even hurling ice cubes at a patio, or slapping a wet flannel into a sink or shower hard enough to make an explosive thwack! seems to work for some. “It’s the fast movement,” she says. ”It’s so satisfying. That kinetic energy is away from you and into another surface.”

One of her clients chose to whack a mattress with a tennis racket, while beating a pile of coats with a wooden spoon is also popular; anything to get the frustration out, without injury or damage. “Piles of soft furnishings, cushions, coats – they’re really good because you get that sense of impact. You can go nuts on it because it’s not getting damaged and no one can hear – it’s the muffling.”

Other clients took up karate, or set out on long hikes, while Cox has a particular soft spot for running crossly, “where you’re just letting everything flail about”. But exercise generally is useful in burning off excess anger: “Something is leaving you and going somewhere else, and most of us have too much of it in us, whether we call it anger or not. Probably, we call it something like frustration.”

Some research has suggested that, far from being cathartic, punching pillows or smashing plates can actually increase aggression. One study conducted by Brad J Bushman, a professor of communication at Iowa State University, involved irritating students by criticising something they’d written, and then asking them to hit a punching bag. It found that participants who were asked to think about the person who angered them while punching felt angrier afterwards, compared with a control group asked to think about keeping fit.

But Cox isn’t simply saying that screaming or whacking things cures anger. Rather, for some women, letting off the excess steam is a first step in tackling whatever is triggering those feelings. “It means your brain can come back online, you can reclaim your feelings, reclaim your thoughts – that’s when you do your deep breathing and centre yourself,” she says. “But that’s when it’s really important to have the conversation because otherwise nothing can change.” For example, an overwhelmed new mother may need to ask her partner to pitch in more; a woman furious about being paid less than male colleagues may need to complain to HR. In some cases, clients ended up pursuing charges over what they recognised as criminal behaviour by a sexual aggressor.

She describes writing the book as cathartic. I wonder if anything still makes her angry now? “I went to a state comprehensive school in a pretty deprived area. Nobody went to Oxbridge; most probably hadn’t even heard of Oxbridge. So I think that’s the only way I did it – by not knowing how impossible it was. And I just think that’s gross,” she says. “We shouldn’t be living like this, where it’s all flying by the seat of your pants and if you get lucky.” Women who can’t afford therapy to explore their anger should, she argues, at least have free access to a community where they can discuss it openly – which is why she started the podcast.

But the ultimate aim isn’t, she says, never to feel angry again. “[Anger] is there for a reason. We have it as part of our apparatus because we need to respond to it, and ideally make change happen because of it.” Rather, it’s to turn anger into something women can use: a way, ultimately, of taking back control.