1. Physical examination: The doctor will examine you physically. Your symptoms and medical history will also be evaluated.
2. Nasal speculum: A bright light and an instrument, called a nasal speculum, will be used for visualizing the nasal septum by opening the nostril.
3. Fiber-optic nasal endoscopy: This test provides a detailed picture of the nasal passage to detect any abnormalities that may be obstructing breathing using an endoscope.
4. X-ray: An x-ray may be recommended to have a better look at the bone structure of the nose.
5. CT scan: This is a type of imaging test in which a series of x-rays and a computer are used to obtain clear images of the nose.

Most cases of nasal septum deviation will not require any treatment. Symptomatic relief can be obtained by the use of certain medications and non-surgical treatment methods. Severe cases of nasal septum deviation may require surgery.
The following are the different types of treatments for nasal septum deviation:

1. Non-surgical treatment: This type of treatment is primarily used to relieve the symptoms associated with deviated nasal septum. The different types of treatments include:

• Decongestants: These medicines are used to treat blocked or stuffy nose by reducing nasal tissue swelling. They may be used orally or in the form of a spray.
• Antihistamines: These medicines help in preventing allergy symptoms, including a runny or stuffy nose. They may also be given in non-allergic cases like a cold.
• Nasal strip: It is a type of adhesive bandage applied across the nose and at the sides of the nostrils. It helps in improving breathing, preventing snoring, and providing better sleep.
• Nasal steroid spray: Prescribed corticosteroid spray can help in reducing the swelling in the nasal passage and aid with drainage.

2. Surgical treatment: Medications only help in relieving the symptoms associated with a deviated nasal septum. However, surgery may be required to correct the condition. The different types of surgeries performed may include:

Septoplasty surgery:

• This procedure may be done under local anesthesia (the surgical area is numbed) or general anesthesia (you will be put to sleep during the procedure). 
• The surgeon makes incisions within the nasal cavity or across the columella (the separating tissues between the nostrils).
• The nasal mucosal lining is then lifted away, along with the membrane covering the septum from one side.
• The mucosal lining on the opposite side is then lifted away in a similar way.
• The deviated septum is then removed. A special mucosal lining is left behind.
• The surgeon may insert silicone splints in each nostril to support the nasal septum.
• Once the septum will be placed in the desired position and straightened, the mucosal lining will be repositioned around it and sutured back together.
• The nose is packed with gauze and bandages may be put on the outside of the nose.
• The procedure takes one to two hours to complete.

Rhinoplasty:

• In some cases, surgery may be performed to reshape the nose at the same time as septoplasty.
• This procedure involves modifying the bone and cartilage of the nose to change its size, shape, or both.

A severely deviated nasal septum may lead to the following complications:

• Nasal blockage
• Breathing difficulty
• Increased susceptibility to sinus infection 
• Dry mouth
• Feeling of congestion or pressure in the nasal passages
• Disturbed sleep
• Loud snoring
• Frequent nosebleeds
• A nasal septum surgery may lead to the following complications:
• Bleeding
• Adverse effects of anesthesia
• Numbness in the upper teeth or gums
• Infection 
• Change in the shape of the nose
• Reduced sense of smell
• Septal perforation (a hole in the septum)
• Septal hematoma (blood collection in the nasal space)

The following are the post-procedure steps following nose surgery:

• You can go home on the same day after the surgery.
• Most patients will notice improved breathing within two to three weeks after surgery.
• Keep the surgical area clean and dry. Use a wet cloth or cotton to clean your face.
• Avoid blowing your nose for the first few weeks after surgery.
• Keep your head in an elevated position while sleeping to avoid bleeding and reduce swelling.
• Change the bandage frequently to maintain hygiene.
• Avoid strenuous activities and heavy exercises for a few weeks after surgery.
• Take as much rest as possible when your body is healing.
• Avoid the consumption of spicy food as they can process the fluid in the nose and complicate recovery.
• Take short walks to remain active during the recovery period to improve the blood flow and relieve the after-effects of anesthesia.
• Avoid wearing sunglasses or spectacles after surgery as they can put pressure on the site of surgery.
• Drink lots of fluids and maintain a healthy weight.
• Take all the medicines prescribed by your surgeon regularly.

Home remedies:

The following home remedies may help in relieving the symptoms associated with a deviated nasal septum:

• Use of steroid nasal sprays
• Treatment of allergies using antihistamines
• Nasal strips to be worn at night before sleeping
• Use of nasal dilators
• Use of nasal valve support to remove the obstruction in the front part of the nose
• Use of neti-pot or nasal irrigations
• Use of vaporizer or humidifier to add moisture to the air
• Take a hot shower bath
• Avoid irritants and food allergens
• Breathing retraining therapy to normalize hyperventilation

Prevention:

A congenital case of nasal septum deviation cannot be prevented. However, the following tips can be helpful in preventing nasal septum deviation later in life:

• Use a helmet or midface mask while playing sports
• Wear your seat belt when traveling in a car
• Wear a helmet while riding a two-wheeler 
• Avoid high-contact sports
• Avoid wearing an extremely tight-fitting mask which may put pressure on the nasal septum 

Cost of nasal septum deviation surgery- 

The cost of non-surgical methods to treat nasal septum deviation in India is between INR 2,000 to INR 10,000.
The cost of surgery to treat nasal septum deviation in Mumbai is between INR 45,000 to INR 70,000.
The cost of surgery to treat nasal septum deviation in Delhi is between INR 40,000 to INR 65,000.
The cost of surgery to treat nasal septum deviation in Bangalore is between INR 40,000 to INR 65,000.
The cost of surgery to treat nasal septum deviation in Chennai is between INR 35,000 to INR 60,000.