Hello and hope you are doing well.
The excessive sleepiness may be because he is not getting adequate sleep at night. It could also be due to sleep disorders. These disorders can be like obstructive sleep apnea, wherein during sleep there is an obstruction to air flow due to laxity of the throat muscles during sleep and this could cause sleeplessness. Hence for therapy CPAP (continuous positive airway pressure) is used to keep it patent. Another cause could be an entity called restless leg syndrome, where there is an odd sensation in the legs during sleep causing the individual to move, which relieves the sensation. These disorders can cause inadequate sleep leading to fatigue and daytime sleepiness. So, I would advise you to consult your primary care physician for further evaluation. He may then ask for a sleep study called polysomnography for further evaluation.
Hope this helped and do keep us posted.
Hi try and get him to a Doctor and ask for a sleep study to be done on him you will probably get your answer there Take care.....Bob