What does dark stripes on the tongue mean?

There are a few potential causes of dark stripes on the tongue:

* Geographic tongue: This is a benign condition that causes patches of the tongue to appear red, smooth, and slightly raised, with white or gray borders. The patches can come and go, and they can vary in size and shape. Geographic tongue is thought to be caused by a combination of genetic and environmental factors, and it is more common in women than in men.

* Fungal infection: A fungal infection of the tongue, such as oral thrush, can cause dark stripes or spots on the tongue. Oral thrush is caused by an overgrowth of the Candida fungus, which can occur in people who have a weakened immune system, such as those with HIV/AIDS or cancer.

* Vitamin B12 deficiency: A deficiency of vitamin B12 can cause the tongue to appear pale, smooth, and red, with dark stripes or spots. Vitamin B12 is essential for the production of red blood cells and for the proper functioning of the nervous system.

* Smoking: Smoking can cause the tongue to appear dark brown or black. This is due to the deposition of tar and nicotine from cigarettes on the tongue.

* Certain medications: Some medications, such as antibiotics, can cause the tongue to appear dark. This is usually a temporary side effect that goes away after the medication is stopped.

If you are concerned about dark stripes on your tongue, it is important to see a doctor to rule out any underlying medical conditions.