Research has found that long-term caffeine consumers can aggravate chronic kidney disease and may increase the risk of kidney stones. This might disappoint all those who start their day with a cup of coffee or tea. Also, soda and energy drinks are equally dangerous if you already have issues with your kidneys.
Caffeine is considered to be a mild diuretic which affects the kidneys’ capability to absorb water. Excessive amounts of caffeine in your system restricts the kidneys from accessing enough water to do their job, but in reasonable amounts, caffeine does not cause much problem.
People with high blood pressure should also stay away from caffeine as it stimulates blood flow and thereby increases blood pressure.