Gingivitis is inflammation of the gums — the redness, swelling, and bleeding that appears when plaque accumulates along the gum line. Poor oral hygiene is the usual cause, but nutrition plays a supporting role: severe vitamin C deficiency produces the bleeding gums of scurvy, and general malnutrition impairs the gum tissue’s ability to resist infection. Smokers, diabetics, and pregnant women are more susceptible. The condition is reversible — thorough brushing, flossing, and professional cleaning restore healthy gums — but if neglected it can progress to periodontitis, where the supporting bone is destroyed and teeth loosen. Dentists regard bleeding gums as an early warning never to ignore, whatever the underlying mix of causes.