N2 nicotinic receptors are found in the brain, plus the autonomic and parasympathetic nervous systems [1]. Different subunits make up these two types of nicotinic receptor, which is why we consider them separately. Muscarinic receptors have a different mechanism of action.
Your body weight can regularly fluctuate, but the persistent, unintentional loss of more than 5% of your weight over 6 to 12 months is usually a cause for concern. You should pay particular attention if you experience other symptoms, such as tiredness, loss of appetite and a change in your toilet habits.
Medical Causes of Obesity Obesity is usually the result of overeating, but in a small percentage of people excess weight gain is a symptom of another disease. Medical causes of obesity can include: Hypothyroidism. This is a condition where the thyroid gland, located in the neck, produces too little thyroid hormone. Thyroid hormone regulates our metabolism. So too little hormone slows the metabolism and often causes weight gain.