Coffee — it's an essential part of daily life for many of us. A ritual. Something we seek soon after getting out of bed.

But it also contains caffeine, a drug more powerful than we realise.

A woman named Heidi recently contacted the ABC Radio Perth Afternoons program and said that if she did not have a coffee for 10 hours, she suffered from nausea, headaches and shaking.

She said she tried to not let too much time pass between brews.

While her symptoms might sound extreme, they are not uncommon or surprising, according to Laura Bajurny from the Alcohol and Drug Foundation.

"Coffee can be quite addictive and it is a drug, which is something that is easy for us to forget considering how important it is to many people's lives.

"Your body becomes physically addicted, which means that if you have coffee regularly over time your body gets used to having caffeine in the system.

"Then when you take it away your body misses it, and that's when you go through a period of withdrawal.

"And then there is also the habit element; coffee can be very social. There can be a real ritual element to it and the habitual part can be really difficult for people trying to cut back to let go of."

For many people, drinking coffee is part of their social lives. ( ABC Radio Perth: Emma Wynne )

Blocking sleepiness in the brain

Caffeine is a stimulant, Ms Bajurny explained, and a powerful means to avoid feeling sleepy.

"It actually works by binding to some of the receptors in your brain that normally pick up a chemical that we produce naturally that makes us tired over time," she said.

"It sits in that chemical's slot so that the chemical can't get in there and it prevents those feelings of tiredness for a prolonged period of time."

The good news is that it's extremely difficult to overdose or die from drinking too much coffee.

"You would have to consume about 80 cups of strong coffee, one after the other, in order to overdose," Ms Bajurny said.

Children and teenagers, however, are more susceptible to caffeine poisoning, which they might consume in high doses through cola and energy drinks.

For most people, the caffeine withdrawal hangover is the most likely consequence of their daily coffee habit.

"A lot of people get headaches, you might have tremors; it's almost the opposite feeling of the coffee," Ms Bajurny said.

"People can feel very sluggish, sleepy, very irritable, even a bit nauseous."

The possible health effects

Of course, there's a lot of research into coffee and some of it suggests there can also be beneficial effects for some conditions from moderate consumption.

But the long-term effects of heavy daily coffee drinking were not well understood by most of the public, Ms Bajurny said.

"The regular heavy use of caffeine may increase your risk of things like osteoporosis, high blood pressure and heart disease, infertility," she said.

"It is also linked to heartburn, ulcers, anxiety and depression and difficulty sleeping.

"If you are having more than four cups a day, you may be putting yourself at risk for those long-term problems and you may want to think about cutting down."

Combining caffeine with alcohol, such as in an espresso martini or alcohol mixed with an energy drink, also places pressure on the body and should be enjoyed in moderation, according to Ms Bajurny.

"You are giving your body a depressant and a stimulant at the same time.

"It's hard on your heart, it sends mixed signals to your body."

Don't go cold turkey

But for someone like Heidi who is concerned about their coffee habit, the best way forward is to simply reduce consumption slowly.

"I would start with the last coffee you have in a day and cut it out; move forward from there," Ms Bajurny said.

"If you do that you won't feel the same effects of withdrawal.

"You could also ask your barista for a weak coffee.

"If you can bear to go decaf, then try that."