Pyorrhea (also known as pyorrhea alveolaris or, in modern terms, periodontitis) is a serious, progressive inflammatory disease of the gums and supporting structures around the teeth, caused primarily by long-term buildup of bacterial plaque and tartar leading to chronic infection. It begins as gingivitis (reversible gum inflammation with redness, swelling, and bleeding) but advances to destroy the periodontal ligament and alveolar bone that anchor the teeth, resulting in deep periodontal pockets between teeth and gums, receding gums exposing tooth roots, persistent bad breath (halitosis), pus discharge from gums, loose or shifting teeth, pain when chewing, and eventual tooth loss if untreated. Common signs include gums that bleed easily (especially during brushing), sensitivity to hot/cold, elongated-looking teeth due to recession, and sometimes abscesses or fistulas. It affects a large portion of adults worldwide, with risk factors including poor oral hygiene, smoking, diabetes, genetic predisposition, stress, certain medications, and systemic diseases.