The Common and Uncommon Side Effects of Caffeine

Uncommon Side Effects of Caffeine

The following are some of the uncommon side effects of caffeine that may occur in high doses (more than 400 mg per day for healthy adults and more than 200 mg per day for pregnant and breastfeeding women) or in people who are very sensitive to it.

1. Rhabdomyolysis

This rare but serious condition involves the breakdown of muscle tissue and the release of a protein called myoglobin into the bloodstream. This can damage the kidneys and cause acute kidney failure.

Caffeine can increase the risk of rhabdomyolysis by increasing muscle activity and metabolism and interfering with calcium and potassium transport in muscle cells. Other factors, such as trauma, infection, drugs, or extreme exercise, can also cause rhabdomyolysis.

The symptoms of rhabdomyolysis include muscle pain, weakness, swelling, dark urine, and reduced urine output. If you suspect you have rhabdomyolysis, seek medical attention immediately³.

2. Addiction

Caffeine can cause physical and psychological dependence, meaning that you may feel the need to consume it regularly and experience withdrawal symptoms if you stop or reduce your intake.

Caffeine withdrawal symptoms can include headache, fatigue, irritability, difficulty concentrating, depressed mood, and flu-like symptoms. These symptoms can start within 12 to 24 hours of stopping caffeine and last for up to 9 days.

Caffeine addiction can also affect your behavior, such as causing you to spend a lot of time and money on obtaining and consuming caffeine or interfering with your social, occupational, or recreational activities.

To prevent or overcome caffeine addiction, you can gradually reduce your intake, substitute caffeine with other beverages, and seek professional help if needed⁹.

3. Hypertension

Caffeine can temporarily raise blood pressure by stimulating heart rate and constricting blood vessels. This effect is usually mild and short-lived and does not cause hypertension (chronic high blood pressure) in most healthy people.

However, some people may be more sensitive to the blood pressure-raising effect of caffeine, especially if they have a genetic variation that affects how they metabolize caffeine or if they have an existing cardiovascular condition, such as hypertension, heart disease, or arrhythmia.

If you have high blood pressure or a heart condition, consult your doctor before consuming caffeine and monitor your blood pressure regularly⁵.

4. Rapid heart rate

Caffeine can increase your heart rate by stimulating your nervous system and increasing your adrenaline levels. This can make you feel more energetic and alert, but it can also cause palpitations or a sensation of your heart beating too fast, too hard, or irregularly.

This effect is usually harmless and temporary and does not affect your heart health in most cases. However, some people may be more prone to caffeine-induced palpitations, especially if they have a low tolerance to caffeine or if they have an underlying heart condition, such as a congenital heart defect, a valve disorder, or an arrhythmia.

If you experience frequent or severe palpitations, seek medical attention, as they may indicate a more serious problem⁹.

5. Fatigue

Caffeine can help you overcome fatigue and drowsiness by blocking the action of adenosine, a brain chemical that makes you sleepy.

However, caffeine can also cause fatigue in some situations, such as when it wears off, when you consume too much, or when you disrupt your sleep cycle. When caffeine wears off, you may experience a crash or a rebound effect, where you feel more tired than before. This can lead to a cycle of caffeine dependence, where you need more caffeine to stay alert and avoid withdrawal symptoms.

When you consume too much caffeine, you may feel exhausted, as caffeine can overstimulate your nervous system and deplete your energy reserves. When you disrupt your sleep cycle, you may also feel fatigued, as caffeine can interfere with your sleep quality and quantity and affect your circadian rhythm, which is your natural 24-hour cycle of sleeping and waking.

To prevent or reduce caffeine-related fatigue, you can limit caffeine intake, avoid consuming it late in the day, and maintain good sleep hygiene³.

6. Urinary Changes

Caffeine can affect your urinary system in various ways, such as increasing your urine output, changing your urine color, or causing urinary incontinence. Caffeine can increase your urine output by acting as a diuretic, making your kidneys produce more urine.

This can help flush out toxins and excess fluids from your body, but it can also cause dehydration and electrolyte imbalance if you lose too much water and minerals. Caffeine can also change your urine color, making it darker or lighter, depending on how much water you drink and the caffeine you consume.

Caffeine can also cause urinary incontinence, which is the involuntary leakage of urine. This can happen because caffeine irritates your bladder and increases your bladder pressure, making it harder to hold your urine. This effect is more common in women, especially those who have a history of urinary incontinence or who are pregnant, menopausal, or elderly.

To avoid or minimize caffeine-related urinary changes, drink plenty of water, limit caffeine intake, and practice pelvic floor exercises².