A teenage girl was diagnosed with acute hepatitis and liver damage after consuming too much green tea that she bought over the internet to lose weight.

Doctors initially believed that the unnamed patient, who was drinking three cups of the tea everyday, had a urinary tract infection.

The 16-year old suffered from nausea, dizziness, joint and stomach pains. She also suffered from jaundice, which caused her skin and the whites of her eyes to turn yellow.

Doctors eventually realized that she had hepatitis, an inflammation or swelling of the liver, which can be attributed to a virus or when the liver was exposed to certain substances such as alcohol.

The teenager, whose case was described in a study published in journal BMJ Case Reports on Sept. 23, said that she had not taken any illegal drugs or over-the-counter medicines and denied drinking alcohol.

She had not also been to other countries abroad recently where she could possibly have contracted the hepatitis-causing virus. She did not also have a blood transfusion.

The girl, however, admitted buying Chinese green tea over the internet having heard that it could help with weight loss.

She told the doctors that she bought two boxes of 100 bags of the green tea online to lose weight and that she was drinking three cups of it for a few months. She was not aware what was in the tea though because most of the ingredients were written in Chinese.

Although green tea has been lauded for a number of health benefits such as providing protection against dementia and Alzheimer's as well as improving cholesterol levels, doctors identified the drink as the possible cause of the girl's health problem and told her to stop drinking it.

Sebastian Thomas Lugg, from University Hospitals Birmingham, and colleagues, who wrote the paper, reported that after ceasing her consumption of the green tea, the girl had rapid and sustained recovery from her illness.

The researchers said that chemicals that were added to the tea possibly to help with weight loss or the pesticides used on tea trees may have contaminated the infusion.

They said that the existence of pesticide-induced hepatitis is possible particularly from less regulated products that were bought from developing countries over the internet.

Donna Seger, from the Tennessee Poison Center in Nashville, said that she is often concerned when people purchase herbal supplements or tea online without knowing a lot about where the product came from.

She said that there are still a lot of people who do not realize that because a product is natural they are not significantly toxic. She said that the liver, which filters out toxin, is usually the first organ that indicates something is wrong.

The 16-year old patient said that she has learned her lesson and that she would not buy tea or weight loss products over the internet again.

"I will never buy any online tea again or any weight-loss pills," the patient said. "People should be more aware of what they are buying and the side effects."

Kalle Gustafsson | Flickr