Hi, Severe headache after cold is usually due to sinusitis in which the sinuses get congested or have fluid or pus into it. This can best be diagnosed and treated as follows: * CT scan alone can diagnose the exact cause whether in sinuses or in head * Consult an ENT surgeon for proper clinical evaluation, examination and investigations * You will be started an an antibiotic, decongestant and an anti-inflammatory medicines Use Otrivin like decongestant nasal drops and take steam inhalation. Take bed rest and plenty of oral fluids. Take care. Hope I have answered your question. Let me know if I can assist you further. Regards, Dr. T. Chandrakant, General Surgeon