Why do you get nose blocks ?

Nasal blockage makes your breathing uncomfortable and is quite distressing if it lasts for a longer duration. The commonest cause of nasal block is cold or flu.
The other causes include Allergic rhinitis, Sinusitis, Deviated nasal septum, Trauma to the nose, Polyps, Benign masses such as Angiofibromas or Inverted papilloma and rarely Malignant tumors arising from the nose or adjoining sinuses. Also it may be due to hormonal causes as in Pregnancy usually during the end of the first trimester.

Generally, nose blockage can be managed with certain simple home remedies such as steam inhalation with eucalyptus, intake of warm water & hot soups, sleeping with head slightly elevated with pillows and use of OTC medications and nose drops.
With these measures the nose block usually is cleared away in 2-3 days.

But if the problem persists for more than 5 days making the patient uncomfortable, then it is the right time to visit an ENT specialist. The other reasons would be symptoms in addition to nose blockage such as Persistent fever, Greenish colored discharge from nose or blood tinged discharge and if you have trouble breathing.
The doctor will determine the cause of nasal blockage. He may perform a nasal endoscopic examination in his office and/or ask for special investigations like CT scan of the nose & paranasal sinuses, blood parameters or allergy testing. The treatment depends on the condition and the cause for nasal blockage.