The lap band surgery is indicated in the following conditions:

1. Having a body mass index (BMI) (calculated by weight in kgs divided by height in meter sq.) of more than 40
2. Having a BMI of 35 to 39.9, with the presence of at least one serious health condition like high blood pressure, diabetes, or obstructive sleep apnea
3. Having a BMI of 30 to 34.9 with diabetes or metabolic syndrome, that cannot be controlled by medical therapy
4. An exception is an Asian patient who tends to have more fat accumulation in the stomach area, known as central obesity, having poorly controlled diabetes, though the BMI may be as low as 27.5

Obesity is fairly self diagnostic and can be determined with a simple physical exam by a doctor. However, the doctor may perform certain tests to determine the level of obesity and the presence of other obesity related disorders. The following diagnostic procedures may be followed.

1. Physical examination: The doctor will evaluate your overall health status, along with your medical history and family history.
2. Blood tests: The various blood parameters are checked using a blood test, and also if there is an underlying medical condition like diabetes or thyroid diseases.
3. Nutrient screening: The levels of various nutrients in the body, like vitamin B-12, iron, folic acid, and vitamin D, are checked.
4. Chest x-ray: This test helps in checking the internal organs like lungs and heart in the chest area.
5. Electrocardiogram (ECG): This test helps in measuring the electrical activity of the heart and diagnosing the various heart disorders that may be present.

The procedure is performed under general anesthesia. The abdomen is cleaned using an antiseptic solution.
The procedure may be performed by making incisions (cuts) in two ways:
1. Laparoscopically: The surgeon makes many tiny incisions (approximately one-quarter to half an inch in size) in the abdomen region. A long tube with a camera on one end, known as a laparoscope, is inserted inside along with other small surgical instruments through the incisions.
2. Open surgery: In the case of open surgery, a single, large, 10 to 12-inch incision is made in the abdomen.
The surgeon will then place an adjustable gastric band (a soft silicone ring) through the incisions around the upper stomach region.
The band can be tightened for creating a small stomach pouch. The surgeon will then place a small device called a port under the abdominal skin, and then attach the band to the port by a thin tubing. Saline or saltwater can be injected or removed through the skin. The saline can flow into or out of the silicone band. Injecting saline helps in filling the band and making it tighter.  This way the band can be loosened or tightened to improve loss of weight and reduce the side effects. The surgical instruments are then removed and the incision site is closed using sutures (stitches) and sterile tape. The procedure takes half an hour to one hour to complete.

The complications associated with a lap band surgery include:

• Allergic reactions
• Breathing problems
• Blood clot formation
• Blood loss
• Infection
• Stroke (when the blood supply to the brain is stopped)
• Heart attack
• Injury to abdominal organs like stomach, intestines
• Heartburn (burning sensation in the chest)
• Stomach ulcers
• Hernia
• Gastritis (inflammation of the lining of the stomach)
• Wound infection
• Bowel blockage due to scarring
• Poor nutrition due to reduced intake of food
• Regaining all the lost weight 
• Pouch dilation
• Band slippage

1. It is normal to have some nausea and pain after the procedure.
2. The doctor may prescribe pain medications to ease the pain and discomfort.
3. You will most likely stay in the hospital for one or two days after the procedure.
4. You will be discharged once your vitals are stable, pain is in control using oral medicines, and you can drink an adequate amount of fluids.
5. The patient is encouraged to get up and move around as soon as possible. This helps in quicker healing and prevents blood clot formation.
6. You will be encouraged to do deep breathing exercises using a plastic device known as an incentive spirometer, to prevent pneumonia.
7. You will be on a clear liquid diet for the first two weeks following surgery. You will then slowly progress to pureed foods, then soft foods, and then your normal diet.
8. Do light exercises or walk regularly after the procedure.
9. Avoid strenuous activities for three to six weeks after the surgery.
10. Avoid heavy lifting for six weeks after the procedure.
11. While showering, wash your wound site with mild soap and pat dry the skin gently using a clean towel.
12. Drink at least 1.5 to 2 liters of water every day.
13. Avoid swimming or taking a bath till your doctor tells you to.
14. Avoid driving for at least one week after the procedure, or till you have stopped all pain medications.
15. Take nutritional supplements daily as directed by your doctor.

Contact your doctor immediately if you notice the following symptoms:

• Fever
• Abdominal pain that is not relieved by taking medicines
• Swelling, redness, or thick green or yellow drainage from the wound site
• Difficulty in breathing
• Chest pain
• Persistent nausea
• Vomiting
• Redness, pain, or swelling in the calf or leg

Follow-up appointments are needed with your surgeon for band adjustments, which are essential for sustainable or maximal loss of weight.
The doctor will monitor you for any long-term complications like weight regain, pouch dilation, and band slippage that may require band removal, revision surgery, or conversion to another type of weight-loss surgery.
Regular and lifelong follow-ups are required with a bariatric dietitian to ensure healthy eating habits and for monitoring any nutritional deficiencies that could occur due to a reduced intake of food.
A bariatric support group or a psychologist may help you in coping with the psychological effects of weight-loss surgery and obesity, and any difficulties that you may be having in coping with a healthy diet and lifestyle.