Brown gums may be due to:
- Melanin
Gums may appear darker if the skin is darker coloured. Melanin gives the skin its colour. The more melanin one has, the darker the skin and gums will be. If the brown gums are due to melanin, it should be present from a young age and the gum colour should remain relatively constant. - Medication
Antibiotics like Minocycline can cause discolouration in the skin, gums, nails, teeth and bones when taken over the long term. Brown gums may be a side effect of Minocycline usage. - Addison's disease
Addison's disease is an autoimmune disease of the adrenal glands, which make a variety of hormones. In Addison's disease, the adrenal glands produce an excess adrenocorticotrophic hormone (ACTH) on the melanocytes and cause them to produce melanin. The lips and gums thus become hyperpigmented and may appear brown.
