Heart palpitations. Dizziness. Nausea. Numbness. Trouble breathing. Chest pains. An all-encompassing feeling of dread.

Heart attack? No, for many people these are the unpleasant symptoms of something much more mundane, a panic attack. They often seem to appear out of the blue. And the first time in particular, before you know what’s happening, they can be terrifying.

“I felt like I was dying,” said a friend who told me he had experienced what he now believes were panic attacks during a period of stress several years ago. Another told me that hers manifested as heaviness in her chest combined with a “sense of doom”.

In my case, I was one of those people terrified I was having a heart attack when I woke up in the middle of the night feeling numbness in my fingers, with my heart racing.

Panic attacks, or “anxiety attacks”, affect about 2 per cent to 3 per cent of Americans in any given year, according to the Anxiety and Depression Association of America. The National Institute of Mental Health reports that about 5 per cent of US adults experience panic attacks at some point in their lives.

These attacks are not uniform from person to person, but do share characteristics.

Along with the earlier mentioned symptoms, there can be sweating, trembling or chills, as well as the fear of losing control, or even the fear of dying. A panic attack is considered “limited” when fewer than four symptoms are present. An individual can have a stand-alone incident, or multiple attacks over time, known as “panic disorder”.

Studies suggest panic attacks are more common in women than men, generally last ten minutes or less and can materialise when a person is perfectly calm, or when they are anxious about something going on in their lives.

Panic attacks are not life-threatening, even if they can feel that way.

And because they are unpredictable, often happening without warning for many people, worrying about future episodes can be particularly debilitating and have a significant effect on quality of life.

According to researchers, stress can be one cause of panic attacks, but genetics and temperament may also play a role, including a history of anxiety or other mental illness in biological relatives

When I described my symptoms to my doctor, I was surprised she said that it sounded like I had “textbook” anxiety. “But I’m a calm person,” I told her. But several stressful events had occurred in my life before my first, and subsequent, panic attacks: my father had died, we had moved and both my husband and I had changed jobs.

Also, anxiety was diagnosed in my father. He had treated it occasionally with medication, which could suggest a genetic predisposition.

The suddenness of the attacks is what is so unsettling the first time.

Allison Clark, a 32-year-old marketing specialist for a tech company who lives in San Diego, had her first panic attack in 2017 when she was finishing her master’s degree, planning a wedding and working full time.

One minute she was touring a potential wedding venue; the next she was light-headed, had the shakes and heaviness in her chest.

“The best way I can describe experiencing a panic attack is getting this rushing feeling of something horribly wrong ... and feeling like you have no control to stop it or make it better,” she said. “Almost like being delivered terrible news where your heart drops and you feel like you’re in a bad dream.”

The terror induced by those sudden symptoms is what often sends many people, including me, to a hospital emergency room certain that something is going horribly wrong, said Reid Wilson, a psychologist who directs the Anxiety Disorders Treatment Centre in North Carolina, and wrote Facing Panic: Self-Help for People With Panic Attacks.

“The most likely event when you’re having a panic attack, at least the first one, is to end up in the emergency department,” Wilson said.

A hospital visit can rule out heart attack or other serious medical problems, and hearing that it is “just anxiety” can be reassuring. But if there is no follow-up, the issue can persist, Wilson said.

One panic attack can lead to others, creating a “panic cycle”.

If your first panic attack was in a grocery store, you may start worrying it will happen again the next time you are doing the weekly shopping, Wilson said, and sometimes that fear seems to prompts another attack.

That happened to Clark: she started having more panic attacks as the wedding got closer. “Some days even the word ‘anxiety’ or ‘panic attack’ would send me into an episode,” she said.

Wilson said it is important for anyone who has a panic attack to be given advice about how to manage the situation in the future, including relaxation techniques to calm your breathing and relax your body.

Consider contacting a doctor if the fear of future attacks persists and begins to affect daily life, or if attacks happen again.

Learning more about why panic attacks happen in the first place can help those suffering from them, too.

“What happens is a whole spectrum of physiological symptoms that occur when a person is under threat,” said James Griffith, the chairman of Psychiatry and Behavioural Sciences at George Washington University School of Medicine and Health Sciences. “During a panic attack, our body’s sympathetic nervous system ignites a ‘fight or flight’ response, even though there’s nothing tangible to fight or flee from.”

Treatment often means helping someone recognise that this threat response is irrational, often through cognitive behavioural therapy: recognising a panic attack for what it really is, and that it won’t last long, and using calming techniques including meditation, deep breathing and muscle relaxation.

Sometimes medications, such as benzodiazepines, including Xanax, are prescribed for short-term use if panic attacks are frequent or particularly disabling.

Whether with medication, therapy, self-learnt coping mechanisms or a combination of various techniques, “it’s a common and generally treatable disorder”, Griffith said. “The steps that need to be taken are to get an accurate diagnosis and get into the hands of someone who treats anxiety. There’s not a panic attack that you can’t stop.”

Clark said a combination of therapy, meditation and other mindfulness practices helped to break the cycle that developed after that wedding venue visit; she hasn’t had a panic attack in nearly a year. Some people can learn to deal with the attack by letting the feeling “wash over them, like waves on the beach”, Griffith said.

I count myself in this category. For me, following up with a general practitioner after my hospital visit and being diagnosed properly was immediately relieving. Knowing what was happening made the events far less scary as they occurred.

I still wake up with my heart pounding from time to time. I’ve learnt effective coping techniques and my attacks don’t last long, sometimes I can stop them before they really get going.

But I look forward to the day when I won’t have these episodes any more. For now, I get by with methodically slowing my breath, and a mental reminder: “This is just a panic attack. Everything is OK. And you’re OK, too.”

• Cara McDonough is a freelance writer living in New Haven, Connecticut. She writes about family, women’s issues and other subjects, and blogs about life in general at caramcduna.com