In recent years, my neck is always hurting, and my shoulders ache as well especially after a prolonged period of lowering the head. Also, I have mild headaches, dizziness, and numbness in arms at the same time. I think that is connected to my job.

In general, neck pain is caused by cervical spondylosis, strain (caused by sleeping posture or exercise) and trauma (caused by accident). According to your description, I think you have been suffering from cervical spondylosis for years.

A week ago, I saw white dots and flashing light, then my eyes began to feel uncomfortable. After that headache started on the right side when I am working on the computer. However, my eyes feel no pain when I am in a dark room.

According to your symptoms of one-sided headache and eye pain, you may have a migraine, a type of headache that is caused by a blockage in blood vessels of the brain.

Three years ago, when I began to work, my menstrual cycle, especially in winter, has become irregular and I experience various physical changes like cramps in the lower abdomen, body fatigue and a painful waist.

Based on what you have described, I suggest you firstly undergo tests to find out what lies behind the menstrual cramps as they can be caused by primary dysmenorrhea and secondary dysmenorrhea as well as by tumours or other gynaecological diseases.

Three weeks ago, I had difficulty passing stools which contained some blood, but I just ignored it because I had experienced it frequently before, especially when I was busy.

Based on your description, I primarily diagnose you may have a digestive problem and are especially prone to ulcerative colitis which is an inflammation of the big intestine, not cancer.