For long-term nasal congestion, first, try saline nasal sprays or rinses to keep the nasal passages clean and moist. Avoid allergens and irritants like dust and smoke. Use a humidifier to add moisture to the air. Nasal decongestant sprays can provide temporary relief but should not be used for a long time. If allergies are the cause, take antihistamines as prescribed by a doctor. In some cases, surgical options may be considered if there are structural problems. Keep warm and avoid cold air. Steam inhalation can also help open up the nasal passages. If the problem persists, consult an ear, nose, and throat specialist for a proper diagnosis and treatment plan.