1. Cancer
The first disease on the list is cancer. I know you might be wondering how laughter can help in treating cancer, but relax you are about to learn something interesting.
First of all, having a good laugh can prevent cancer, because intense physical or mental stress can weaken our immune system. And a weakened immune system is one of the major causes of cancer.
Secondly, the act of using laughter to improve overall health and wellbeing is called the laughter therapy. Laughter therapy has been used in the treatment of cancer, how so? Laughter induces physiological and biochemical changes in our body that have an astounding effect on the development of cancer.
By integrating laughter therapy along with the conventional cancer treatments, the overall healing process from cancer is greatly increased. Laughter therapy for cancer patients is used to increase their positive thoughts, combat their negative thoughts and enhance their mental wellbeing, as well as inducing physical changes.
At the Cancer Treatment Centers of America (CTCA), this laughter therapy is extensively used. They offer humour therapy sessions or laughter club , to help cancer patients and their families use and enjoy laughter as a way to enhance the healing process. The patients don't even need to fInd anything funny to genuinely laugh about because the therapy uses fake or forced laughter, which works. This is because whenever the patient laughs the brain releases endorphins, which acts as the body's natural painkiller, and mood enhancer.

2. Depression
Depression is a mental illness, that negatively affects thoughts feelings and actions. Depressed people normally have negative thoughts and are emotional weighed down. However, depression can be prevented, treated and diagnosed with laughter therapy.
There are many methods for treating depression, but laughter therapies are fast gaining ground as an effective treatment. Laughter yoga or laughter exercises is one of the ways laughter is used to treat depression. Laughter yoga incorporates yoga techniques, breathing exercises and playful laughter to treat depression and other mental or emotional problems.
Laughing with other people is one of the best way to combat depression with  laughter as it improves our mood through social connection and an increased feeling of belonging. Laughing with friends can decrease feelings of alienation and lowers our risk for depression.

3. Eczema
Laughter and humour have also been shown to improve the condition of people with eczema.
In a clinical study of 20 patients with atopic eczema, dermcidin (DCD)-derived peptide, an antimicrobial peptide found in the sweat gland, was found to be decreased in these patients. However, after viewing a humorous video, the patients had increased level of DCD.

4. Insomnia
Insomnia is a sleeping disorder characterised by irregular sleep patterns and the inability to sleep properly. Laughter can be used to treat insomnia in many people. Laughing causes the body to produce more melatonin, a hormone released by the brain that helps you sleep better.
Scientific research has also shown that laughter can improve sleep patterns and is an effective treatment for insomnia. Guffawing in the evening, or just before going to bed will help you have  sound night rest.

5. Post-traumatic stress disorder
Posttraumatic stress disorder (PTSD) is a condition that develops following some stressful situation or event. The symptoms are sleep disturbances, recurrent nightmares and lack of concentration.