Why am having fever and lack of concentration

Any other symptoms?: Fever by it self can cause lake of concentration but do you have any other symptoms or cause for the fever? go to the ER immediately if you have headache, flank pain, vomiting or call your doctor immidiatly for other symptoms or concerns. Fore now, take Tylenol (acetaminophen) or Motrin for fever as needed. if your fever improved and you still have lake of concentration then see your doctor for more evaluation.