Digestive and excretory systems

Caffeine increases the amount of acid in your stomach and may cause heartburn or upset stomach. Extra caffeine doesnt get stored in your body either. Its processed in the liver and exits through your urine. This is why you might have an increase in urination shortly after having caffeine. If you have experience stomach problems, like acid reflux or ulcers, ask your doctor if its okay for you to have caffeine.

Circulatory and respiratory systems

Caffeine is absorbed from your stomach. It reaches its highest levels in your bloodstream within an hour or two. Caffeine can make your blood pressure go up for a short time. This effect is thought to be attributed to either an increase in adrenaline or a temporary block on the hormones that naturally widen your arteries. In most people, there is no long-term effect on blood pressure, but if you have irregular heart rhythms, caffeine may make your heart work harder. If you have high blood pressure (hypertension) or heart-related problems, ask your doctor if caffeine is safe for you to consume. An overdose of caffeine may cause rapid or irregular heartbeat and breathing trouble. In rare cases, caffeine overdose can result in death due to convulsions or irregular heartbeat.

Skeletal and muscular systems

Caffeine in large amounts may interfere with absorption and metabolism of calcium. This can contribute to bone thinning (osteoporosis).If you consume too much, caffeine may cause also your muscles to twitch. If experiencing caffeine withdrawal, a symptom may include achy muscles.

Reproductive system

Caffeine travels within the bloodstream and crosses into the placenta. Since its a stimulant, it can cause your babys heart rate and metabolism to increase. Too much caffeine can also cause slowed fetal growth and increased risk of miscarriage. In most cases, a little caffeine is safe during pregnancy. According to the Mayo Clinic, you should limit caffeine consumption between 200 and 300 milligrams per day if youre trying to get pregnant. Theres some evidence that large amounts of caffeine can interfere with the estrogen production and metabolism needed to conceive.