<s>[INST] My friend was telling me that her 4 year old son has not been himself lately he is very weepy and tired, doesn t want to play, has lost 2 and 1/2 kilos in 1 month but says he is still eating and he has been complaining about pains in his legs, she has taken him to her GP and he examined the boy and did a urine test and said he could not find anything wrong with him, he put it down to a growth spurt as he apparently has grown 2cm in the past month. Does this sound right? He is still not back to his usual boistrous and jovial self? What could be wrong with him and what steps should she follow? [/INST] Hi, Any history of fever or any other illness in recent past? Looking tiered and dull, with history of 2.5 kg weight loss over 1 month in a child is something that needs to be evaluated without delay. Sometimes this happens following febrile illnesses like typhoid or IMN (mononucleosis). If no such suggestive history, we need a basic workup to rule out conditions like anemia, chronic infection/inflammation or hematological disorders. If I were his treating doctor, after examining him for pallor and enlarged lymph nodes/spleen/liver, I will order few more tests including a blood count, ESR and peripheral smear. Kindly discuss with a pediatrician. Take care. Hope I have answered your question. Let me know if I can assist you further.  </s>