What are some signs and symptoms of preleukemia and leukemia?

Multiple. Leukemia can present with multiple signs and symptoms including but not limited to: bone pain, refusal to bear weight, gum bleeding, bleeding from other sites, pallor, lack of appetite, fever, night sweats, unexplained weight loss, easy bruising, fatigue, etc. If a concern for leukemia exists, consultation with the primary care physician or a hematologist is recommended.
Feel Unwell, tired. These are serious conditions which are often associated with low blood counts(preluekemia) and typically have associated anemia which causes fatigue, tiredness. Patients often haven fever due to frequent infections due to low white blood cell production. So a blood count(cbc) can give you an easy answer to start with, and it is a good test for screening and for early detection.