A common numbing medication turned a woman’s blood blue

NBC — A 25-year-old woman in Rhode Island gave new meaning to the phrase “feeling blue” when she developed a rare and sometimes fatal condition called methemoglobinemia that turned her blood a deep shade of navy blue.
The woman, whose case was described Wednesday in the New England Journal of Medicine, told doctors that she had used a topical pain reliever for a toothache.The next morning, she woke up feeling sick and went to the emergency room.
“I’m weak and I