8 reasons why coffee is making you sick and how to fix it

Coffee is the lifeblood of Australia. We take our coffee seriously! It could be flat white from our favourite café or a double shot long black to power through the workday... but what happens when your daily cup starts making you feel sick? Stomach churns, trips to the bathroom, headaches... these symptoms aren't normal and yet they effect a large portion of Australia's population.

If you've ever Googled, "Why does coffee make me feel sick?" then you're not alone. Many Aussies experience unpleasant side effects from coffee, including nausea, jitters, headaches, and digestive discomfort. So what’s going on? Let’s break it down.

 

1. High acidity

The Problem

Coffee is naturally acidic, with a pH ranging from 4.5 to 6.0. For comparison orange juice has a pH of around 3.5, while water sits at a neutral 7. If you’ve ever felt a burning sensation in your stomach after coffee it’s likely due to this acidity.

This high acidity can irritate the stomach lining, especially for people prone to acid reflux, heartburn or gastritis. Drinking coffee on an empty stomach can make this worse, as there’s no food to buffer the acid. Over time excessive acidity may contribute to inflammation and discomfort.

The Fix

• Go for low-acid coffee varieties which have been processed to reduce acidity.
• Avoid drinking coffee on an empty stomach and have it after a meal to lessen the impact on your gut.
• Consider switching to a coffee alternative that has a lower acidity profile, such as mushroom coffee drinks.

 

2. Caffeine sensitivity

The Problem

Not everyone processes caffeine the same way. Some people metabolise it quickly, while others feel its effects for hours. If you experience jitters, a racing heart, dizziness or nausea after drinking coffee, you may be caffeine-sensitive.

This sensitivity can be genetic or develop over time due to excessive consumption. Caffeine also stimulates the nervous system which can heighten feelings of anxiety or stress.

The Fix

• Reduce your intake gradually to avoid caffeine withdrawal.
• Try caffeine replacement options such as decaf coffee or low-caffeine drinks.
  

 

3. Artificial additives and dairy sensitivity

The Problem

It’s not always the coffee itself that’s causing issues; it could be what you’re putting in it. Flavoured syrups, artificial sweeteners and processed creamers can introduce chemicals that upset digestion.

Dairy is another culprit. Many Australians are lactose intolerant or have difficulty digesting dairy, leading to bloating, stomach cramps and nausea.

The Fix

• Swap out artificial sweeteners for natural options like honey.
• Try plant-based milk alternatives like almond, oat, or coconut milk, they're usually sweeter.
• Consider whether it’s the coffee or the additives causing your symptoms by testing different ingredients.

 

4. Drinking coffee on an empty stomach

The Problem

Many of us roll out of bed and reach straight for the coffee machine, but this could be setting us up for nausea and digestive issues.

When consumed first thing in the morning, coffee stimulates acid production in the stomach. Without food to balance it out this can lead to irritation, discomfort and even mild nausea.

The Fix

• Always eat something before drinking coffee. Even a banana or a handful of nuts can help.
• Experiment with drinking coffee later in the morning, once your digestive system is more active.
• Consider replacing your morning coffee with a less acidic alternative like mushroom coffee.

 

5. Dehydration

The Problem

Coffee is a diuretic, meaning it increases urine production. This can lead to dehydration, causing headaches, dizziness and general fatigue.

Many Australians rely on coffee as their primary beverage throughout the day, sometimes neglecting proper hydration. Even coffee-flavoured milk is a diuretic. If you're drinking multiple cups without balancing it with enough water you could be drying yourself out.

The Fix

• Follow a one-to-one rule; for every cup of coffee, drink a glass of water.
• Reduce excessive coffee consumption and replace it with hydrating alternatives like herbal teas.

 

6. Overconsumption

The Problem

The average Australian consumes 1.91 kilograms of coffee per year, according to industry data. That’s a lot of caffeine.

Too much coffee can overstimulate the nervous system, causing symptoms like nausea, headaches, digestive issues and energy crashes.

The Fix

• Limit coffee to 1 to 2 cups per day and avoid excessive intake.
  

 

7. Poor-quality coffee beans

The Problem

Not all coffee is created equal. Lower-quality coffee beans may contain impurities, mould, or mycotoxins, which can cause stomach discomfort, headaches, and fatigue.

This is especially common with cheap, mass-produced coffee, which may not undergo rigorous quality control.

The Fix

• Choose high-quality, organic coffee that has been properly sourced.
• If you experience ongoing issues, consider switching to a more premium coffee brand.

 

8. Coffee isn’t for everyone

The Problem

For some people, coffee simply doesn’t agree with them. Whether it’s genetic, digestive or a combination of factors, coffee might not be the best choice for your body.

Common symptoms of coffee intolerance include:

• Nausea or digestive discomfort
• Jitters or anxiety
• Headaches or dehydration
• Stomach irritation or acid reflux

The Fix

If coffee consistently makes you feel unwell, it may be time to explore other options. There are plenty of coffee alternative drinks that provide similar benefits without the downsides.

 

Finding a better alternative

If coffee is making you sick but you still crave a warm, energising drink; you have options. Many Australians are turning to mushroom coffee drinks, and caffeine-free coffee alternatives as a healthier substitute for caffeine.

Some functional ingredients, like lion’s mane mushroom drinks, chaga mushroom coffee drinks, and reishi mushroom drinks, offer energy and focus without the jittery side effects of caffeine. These drinks are gaining popularity in Victoria, New South Wales and Queensland, where more people are looking for natural solutions to their coffee woes.

If you're experiencing coffee withdrawal symptoms or struggling with caffeine detox headaches, swapping coffee for a functional mushroom drink could be a game-changer.

 

What next?

Coffee is an Aussie staple, but it doesn’t always love us back. If you’ve been feeling sick after drinking coffee, the culprit could be its acidity, caffeine content, additives, or even just how you consume it.

By tweaking your coffee routine, or replacing it with a caffeine replacement that’s gentler on your stomach. you can still enjoy a warm, energising drink without the downsides.