One of the symptoms of breast cancer is fatigue.

I distinctly remember how tired I was even before I was diagnosed. My husband came home for R&R (he was deployed when I was DX'd) and I recall just being tired the whole time he was there. In fact I think we went to bed early every single night he was there because I was so fatigued.

It could be a side effect of the cancer, or the stress, or just life in general.

Good luck as you begin your journey.

I was really tired ,and the stress from being diagnosed with BC can be overwhelming.I never knew anyone that had it so I had so much to learn. I didn't find this site till after I finished my treatments. Take one day at a time. Good Luck on your journey you are not alone. Hugs

I agree the stress of the diagnosis and the decisions to be made can add to the fatigue.

It's probably not a side effect of the cancer - more likely the stress of receiving the cancer diagnosis. It's on your mind 24/7 for a while, which is very stressful.
Are you sleeping well? I sure didn't sleep well after my diagnosis. Took a lot of interventions for me to get to sleep before 3 or 4 a.m. in those first months. Even now (almost 10 years later), I use Melatonin to help me sleep. Others use Ambien & other sleep aids with good benefit.