Obesity is rarely just a physiological problem problem. This disorder has far reaching effects; physiological, psychological and social. On the physical front, obesity can lead to several complications that could be fatal or incapacitating if left untreated.

Some of the most common diseases that are directly and indirectly linked to obesity are:

• Type II Diabetes
• Heart Disease
• Hypertension
• Hypercholesterolemia
• Liver and kidney disorders
• Joint Pain/Osteoarthritis/Gout
• Respiratory disorders
• Gastro-esophageal reflux disease
• Infertility
• Certain cancers
• Sleep Apnea
• Depression and anxiety disorders
  

Type II Diabetes
Type 2 diabetes also called non-insulin-dependent diabetes mellitus (NIDDM) has the strongest association with obesity. In type II diabetes, the body does not respond correctly to insulin. In other words, a person becomes insulin resistant. Insulin resistance means that fat, liver, and muscle cells do not respond normally to insulin. As a result, blood sugar does not get into cells to be stored for energy and the blood sugar levels inevitably increase. People who are overweight are more likely to have insulin resistance, because fat interferes with the body's ability to use insulin. Family history and genetics play a large role in type II diabetes. Low activity level, poor diet, and excess body weight (especially around the waist) significantly increase your risk for type 2 diabetes.

Cardiovascular disease and hypertension
Cardiovascular disease (CVD) includes coronary heart disease (CHD), stroke and peripheral vascular disease. These diseases account for up to 33% of deaths in most industrialized countries - a figure that's increasing rapidly in developing countries as well.

Obese individuals are more likely to have higher blood triglycerides (blood fats) and low -density lipoprotein (LDL) cholesterol (bad cholesterol) and lower high-density lipoprotein (HDL) cholesterol (good cholesterol). This is most often seen in obese people with high levels of abdominal fat, and has been consistently linked to a higher risk of CHD. A 10 kg weight loss can produce a 15% decrease in LDL cholesterol levels and an 8% increase in HDL cholesterol.

About 30-65% of hypertension (high blood pressure) sufferers in the West develop hypertension as a result of obesity. Blood pressure increases with BMI; for every 10 kg increase in weight, blood pressure rises by 2-3mm Hg. Conversely, for each 1% reduction in body weight, blood pressure falls by 1-2mm Hg.

The risk of hypertension in overweight adults is nearly three times higher than in non-overweight adults. This risk is nearly six times higher for overweight people aged between 20 and 44.

Cancer
Several studies have found an association between obesity and the incidence of certain cancers, particularly of hormone-dependent and gastrointestinal cancers. Obese women have been proved to be at greater risk of breast, endometrial, ovarian and cervical cancers. There is also evidence for higher risk of prostate and rectal cancer in men. Obesity also increases the risk of colon cancer by nearly 3 times in both men and women.

Osteoarthritis
Degenerative diseases of weight-bearing joints such as the knee are common complications of obesity. The cause of this is mechanical damage to joints due to the excess weight. Lower back pain is also more common in obese people and may be one of the major contributors to obesity-related absenteeism from work.

Psychological aspects
Obese people are stigmatized world over. It is perceived as an undesirable physical appearance, and supposedly embodies several character defects. Even children often perceive obese children in a negative manner.

Obese people face discrimination everywhere. A study of overweight young women in the USA showed that they earn significantly less than healthy women who are not overweight or than women with other chronic health problems.

Sleep Apnea
Sleep apnea is a chronic condition that disrupts sleep. In this condition there are one or more pauses in breathing or shallow breaths while sleeping. These breathing pauses can last from a few seconds to minutes. They often occur 5 to 30 times or more per hour. Typically, normal breathing then starts again, sometimes with a loud snort or a choking sound.

This results in poor sleep quality that makes one feel tired during the day. Sleep apnea is one of the leading causes of excessive daytime sleepiness.

Obesity is a leading cause of sleep apnea. It is more prevalent in older people and is more commonly seen in males.

Diagnosis is based on history and sleep study. Weight loss leads to mark improvement in sleep apnea. Breathing devices such as Bi- Pap are useful and smokers need to quit smoking at the earliest.