Among the possible signs and symptoms of ALL are:
Unexplained and persistent fever
Marked fatigue and weakness
Unexpected weight loss with poor appetite
Easy bruising or bleeding
Leukemia cells that spread to the brain and spinal cord can cause:
Severe and persistent headache
Trouble with balance
ALL is not a common disease. So most often the above symptoms are caused by some other medical condition.
Most often the above symptoms are caused by some other condition, not ALL. However, you should always contact your doctor if you experience any of them.