Background Hypothyroidism is a common endocrine disorder characterized by reduced synthesis or action of thyroid hormones, leading to metabolic slowing and multisystem involvement. Conventional management with levothyroxine may be associated with persistent symptoms, dose variability, and long-term adverse effects. From an Ayurvedic perspective, hypothyroidism can be understood as a Kapha-pradhāna Rasa-pradoṣaja Vikāra with Urdhva-jatrugata sthāna-viśeṣa, resembling Galagaṇḍa, arising due to Agnimāndya, Āma formation, and srotorodha. Case History A 36-year-old female presented with diffuse non-tender neck swelling, progressive weight gain, severe constipation, lethargy, hair fall, dry skin, and heaviness for six months. Laboratory investigations revealed markedly elevated TSH levels suggestive of primary hypothyroidism. Based on Ayurvedic assessment, the condition was diagnosed as Kapha-pradhāna Rasa–Meda duṣṭi. The patient was managed with Deepana-Pachana, Udwarthana, Snehapāna, Classical Vamana, followed by Saṃsarjana Krama and Pratimarsha Nasya with Thumbi Taila, along with supportive Śamana therapy. Results Following treatment, the patient showed marked improvement in bowel habits, appetite, energy levels, skin texture, hair fall, and reduction in neck swelling. Clinical severity scores improved significantly, and thyroid function parameters showed a progressive and sustained reduction during treatment and follow-up, indicating improvement in metabolic and endocrine function. Conclusion This case demonstrates that Classical Vamana followed by Thumbi Taila Pratimarsha Nasya can effectively manage primary hypothyroidism with Kapha-dominant pathology. The integrative Ayurvedic approach addresses the underlying Āma, Agnimāndya, and srotorodha, offering a safe, holistic, and physiologically rational alternative or adjunct to conventional therapy.