Pituitary tumors can kill, that’s for sure. This is because pituitary tumors first cause headaches, nausea, vomiting, and dizziness as they continue to grow in size. If it increases in size and breaks through the saddle diaphragm, it can compress the optic nerve of the optic cross, causing loss of vision and visual field defects. If it enlarges again, it will compress the brainstem, hypothalamus and other parts of the brain, which will cause disorders of these functions. For example, if it compresses the hypothalamus, it will cause disorders of the biological clock; if it compresses the pituitary gland, it will cause diuresis and disorders of endocrine functions. Moreover, there are some endocrine pituitary tumors, which secrete some inappropriate hormones, resulting in the rise and fall of human hormone level, that is to say, the state of disorder, which will cause adverse effects on human body. Therefore, pituitary tumor must be treated actively.