Hi, Development of such a swelling on the right side of neck overnight with sore throat the previous night indicates bacterial infection from right tonsil or pharyngitis causing lymph node enlargement in the drainage area. Rush to your doctor or to ER for clinical examination and investigations: * Tests of throat swab and blood for elevated WBC, to rule out diabetes and any other tests * Ultrasound of neck to see for cause of enlargement and to see if there is any collection of fluid or pus * Complete course of a broad spectrum antibiotic, anti-inflammatory medicine to be followed as would be prescribed * Further management as would be suggested * If there is vomiting or difficulty in swallowing then it would be better to get admitted to the hospital for intravenous fluids and antibiotic Take care. Hope I have answered your question. Let me know if I can assist you further. Regards, Dr. T. Chandrakant, General Surgeon