The 3 most common reasons for a blocked nose are:
1. Rhinitis (sensitive nose) - this can be allergic (if your nose reacts to a protein in the environment, e.g. dust mites, cat or dog furs, pollens etc) or non allergic (if your nose reacts to temperature changes, perfumes, cigarette smoke etc). Common symptoms include blocked nose, clear runny nose, sneezing, itchy eyes and nose as well as postnasal drip.
The main reason for the blocked nose (which is usually both sides but can be worse on one side) is due to enlarged turbinates (medically known as inferior turbinate hypertrophy. The turbinates are sausage-like structures at the side walls of the nose that warm and humidify the air that you breathe in. Treatment usually involves the use of nasal steroid sprays and antihistamines/decongestants. In patients with persistent blocked nose after a good trial of medications, turbinate reduction procedures can be considered.
These include radiofrequency or coblation of the turbinates (which is less aggressive in turbinate reduction but can be done in the clinic under local anaesthesia) and inferior turbinoplasty (which is more aggressive in turbinate reduction but is done under general anaesthesia)
2. Deviated nasal septum - the nasal septum is bony cartilaginous structure that divides the nasal cavity into a right and left side. In most people, it is mildly crooked or bent to one side. If the bent is significant, then one side of your nose may be blocked. It is quite likely that you may have this problem if your blocked nose is just one sided and is worse during a flu. This can be corrected with a minimally invasive surgery called septoplasty (no cuts on the outside of the nose/face). The reason for a deviated septum can be genetic or due to trauma.
3. Sinusitis - this refers to infection of the sinuses. Typical symptoms include coloured or thick nose mucous, pain in the face, blocked nose, postnasal drip and loss of or reduced sense of smell. Treatment includes a course of oral antibiotics, nasal steroid sprays and nose wash (salt water wash). In some cases, nasal polyps (usually benign inflammatory growths that forms from the lining of the nose and sinuses) can occur.
There are many other causes of a blocked nose such as tumours, foreign bodies, systemic disorders etc but these are much less common. I would suggest that you visit an ENT Specialist for an assessment. This will include a nasoendoscopy (nose scope done under local anaesthesia) which is relatively painless and takes minutes to perform.
Hope this helps and all the best!
