Tannins are a family of chemicals found in tea. Tannins may bind to iron in meals, preventing absorption.
Tea leaves naturally contain caffeine. Overconsuming caffeine from tea, or any other source, may contribute to feelings of anxiety, stress, and restlessness
Melatonin is a sleep-inducing hormone. Caffeine may suppress melatonin synthesis, causing poor sleep quality.
Certain compounds in tea may cause nausea, especially when consumed in large quantities or on an empty stomach
Research suggests that caffeine can relax the sphincter that separates your esophagus from your stomach, allowing acidic stomach contents to more easily flow into the esophagus
Intermittent caffeine intake may help relieve certain types of headaches. However, when used chronically, the opposite effect can occur
Although feeling light-headed or dizzy is a less common side effect, it could be due to drinking too much caffeine from tea.
Caffeine is a habit-forming stimulant, and regular intake from tea or any other source could lead to dependence.