The Pituitary is the main part of the brain that controls all your hormones. If there is any irregularity to one part of the pituitary this can cause a wide range of symptoms that can be a sign there could be a tumour growing.
Such symptoms to not disregard as normal and should be checked out by your doctor include:
Weight Gain or Weight loss
Irregular facial hair (eg. on a female)
Unhealthy dry hair
Severe Anxiety or stress
Lactating (when not pregnant)
Irregular Menstrual Cycle
Inability to concentrate
Larger sized feet, hand or head (irregular growth not in proportion with the rest of your body)
There are many more symptoms that are a sign there may be something wrong.