From the Guidelines
Consuming too much caffeine can lead to several uncomfortable symptoms, and it is essential to be aware of these symptoms to prevent morbidity, mortality, and reduce the impact on quality of life. Common signs of caffeine overconsumption include restlessness, anxiety, rapid heartbeat, insomnia, headaches, dizziness, dehydration, increased blood pressure, digestive issues like nausea or diarrhea, frequent urination, and muscle tremors or jitters. More severe symptoms that may indicate caffeine toxicity include confusion, hallucinations, chest pain, irregular heartbeat, uncontrollable muscle movements, convulsions, and in rare cases, death. These symptoms occur because caffeine is a stimulant that blocks adenosine receptors in the brain, increases adrenaline production, and affects various neurotransmitters. Most healthy adults can safely consume up to 400mg of caffeine daily (about 4 cups of coffee), but sensitivity varies between individuals 1. If you experience these symptoms, reduce your caffeine intake gradually rather than stopping suddenly to avoid withdrawal symptoms like headaches and irritability. Staying hydrated can help alleviate some of the milder symptoms of caffeine overconsumption. Some key points to consider:
- The American Academy of Pediatrics recommends that children and adolescents avoid consuming stimulant-containing energy drinks due to the risk of caffeine toxicity 1.
- Caffeine intake should be limited to 200mg per day for pregnant women, as recommended by the European Food Safety Authority 1.
- Energy drinks, which often contain high levels of caffeine, can lead to adverse effects, particularly in adolescents and young adults 1.
- It is crucial to be aware of the amount of caffeine in various beverages, including coffee, tea, and energy drinks, to avoid excessive consumption 1. Overall, being mindful of caffeine intake and its potential effects on the body can help prevent uncomfortable symptoms and reduce the risk of morbidity, mortality, and negative impacts on quality of life.
From the FDA Drug Label
Following overdose, serum caffeine levels have ranged from approximately 24 mg/L (a post marketing spontaneous case report in which an infant exhibited irritability, poor feeding and insomnia) to 350 mg/L. Serious toxicity has been associated with serum levels greater than 50 mg/L. Signs and symptoms reported in the literature after caffeine overdose in preterm infants include fever, tachypnea, jitteriness, insomnia, fine tremor of the extremities, hypertonia, opisthotonos, tonic-clonic movements, nonpurposeful jaw and lip movements, vomiting, hyperglycemia, elevated blood urea nitrogen, and elevated total leukocyte concentration. Seizures have also been reported in cases of overdose.
The symptoms of too much caffeine include:
- Fever
- Tachypnea
- Jitteriness
- Insomnia
- Fine tremor of the extremities
- Hypertonia
- Opisthotonos
- Tonic-clonic movements
- Nonpurposeful jaw and lip movements
- Vomiting
- Hyperglycemia
- Elevated blood urea nitrogen
- Elevated total leukocyte concentration
- Seizures 2
From the Research
Symptoms of Too Much Caffeine
- Cardiovascular and central nervous system toxicity can occur due to caffeine overdose, as reported in a case study 3
- Caffeine can induce panic attacks in patients with panic disorder, with a significant proportion of patients experiencing panic attacks after consuming caffeine equivalent to 5 cups of coffee 4
- Caffeine intake is associated with an elevated risk of anxiety in healthy individuals, especially with high-dose intake (greater than 400mg) 5
- Symptoms of too much caffeine can include tremor, palpitations, and other somatic or autonomic symptoms, which can be alleviated with beta-blocking drugs 6
Treatment and Management
- Early identification and intervention with β-adrenergic antagonists and activated charcoal is crucial in managing caffeine toxicity 3
- Beta-blocking drugs can be effective in treating anxiety disorders, particularly for somatic or autonomic symptoms, and can be used as adjuncts to existing treatments 6