Does Caffeine Affect Everyone The Same?

Caffeine is actually a drug -- a stimulant, to be exact. It takes about 10 minutes after ingesting it to affect you, and about 12 hours to completely exit your system. Just how stimulating it is depends on several factors such as gender, age, medical conditions, medications you take and mental health issues. You can have too much caffeine, be dependent on it, or experience withdrawal symptoms from not getting consistent amounts of it.

Caffeine Sources

Coffee is not the only source of caffeine. Chocolate, tea and over-the-counter pain relievers like Excedrin contain it. Some prescribed medications such as Percocet also have it. Also, soft drinks and energy drinks can contain it. A cup of coffee has about 100 mg of caffeine. A cup of coffee ice cream has 50 mg of caffeine, while a cup of hot chocolate has 7 mg.

Caffeine Effects

The range of effects from caffeine include a feeling of wakefulness to extreme irritability to insomnia. Caffeine raises blood pressure and heart rate. It also increases dopamine, which activates the brain and can make you feel good. Other possible effects are anxiety, restlessness, dehydration, increased urination, heart palpitations, panic attacks, muscle shakes or an upset stomach. Adverse effects are more likely with consumption of over 300 mg per day, or more than four cups of coffee. Some people are more sensitive to caffeine than others.

Irregular Caffeine Consumption

Most individuals can consume 200 to 400 mg of caffeine without issues. Those who do not have it on a regular basis will be more sensitive and more likely to experience negative effects from it, according to the Mayo Clinic.

Gender

Men are usually more affected than women by caffeine. Yet, if you are pregnant, keep in mind that caffeine can enter the placenta and affect your baby. During pregnancy, caffeine consumption should be very limited so as not to increase blood pressure and heart rate in either mother or baby.

Medical Conditions

Those with anxiety disorders could be extremely sensitive to caffeine's effects. Since caffeine increases the release of catecholamines and so does anxiety, this is not a good combination. If you are taking the antibiotic Ciprofloxacin, you might not break down caffeine as successfully. Theophylline is a medication that has similar effects to caffeine and when taken with it could lead to excess consumption. According to a February 2002 study in the journal "Diabetes Care," caffeine reduces insulin sensitivity and therefore is not recommended for those with diabetes.