If you WANT to do something but are too tired it’s fatigue.
If you HAVE to do something you don’t want to do but are suddenly too tired its laziness.
My guess is if you care enough to ask, it’s not laziness.
Here are some possible causes:
DSM – see ADHD
It’s much different than people think it is. Can cause issues getting started with tasks. Looks lazy from the outside, but weird brain chemistry on the inside. If you are always running late or procrastinating tasks or feeling tired specifically when bored it could be this.
A neuropsychological evaluation can check for this with a series of tests.
Depression can make it hard to get out of bed or get motivated even with sufficient rest.
Underlying medical issues can cause fatigue. Some are hard to diagnose and often missed by doctors.
Sleep issues such as sleep apnea and restless leg syndrome’s lesser known cousin perioc limb movement disorder, can interupt your sleep without you being aware of it. If you wake up after a full night’s rest still feeling exhausted could be this.
A sleep study can diagnose.
Digestive issues like celiac disease and IBD-Crohns/UC which is very common among Jews but incredibly hard to get correctly diagnosed.
See a Gastroenterologist.
Thyroid issues and Anemia can cause fatigue. Get a bloodwork panel.
Hope this helps!