Angry tones of boss worry me

I feel my boss keeps anger within himself, being very bottled-up to appear and sound as calm as possible.
Lately he's been sounding more angry with me. He directly mentions things I have done wrong or how I can do things better. But sometimes he gives me orders in an angry tone.
I know I can make rooms for improvement and I feel I still need to be more oriented with my workplace, but I'm getting worried with all those angry tones, I'm worried he's keeping criticisms about me deep inside himself.

Hello. I extend a morning greeting.

My first thought is to talk to Human Resources. There are several reasons for this. First off they obviously need to be advised of this inappropriate behaviour. Secondly, if it seems your manager/boss does feel there is a performance issue, the HR Department should draw up an improvement plan.

Also coming to mind is that you contact your EAP (Employee Assistance Plan). Unless you work for a smal business, you ought to have one.

Finally there is the option to speak directly with this boss of yours. The conversation might go like, "You seem to find an issue with my performance. Can we talk about your expectations? I would like to set up some goals that both you and I can agree upon." Difficult to do and say yes, but i my experience saying something in this manner generally stops the individual in their tracks. After all, they can't argue with it. It shows an indication of taking the job seriously as does it indicate an willingness to do well.

Keep us up to date.

I'm not sure what to tell you to do about your boss (his attitude seems inappropriate to me, too). But I want to offer support...it's mind-wracking to feel you're not measuring up in your boss' eyes.

I like justafriend's idea of speaking with your boss directly.

Thanks for your responses. A direct approach sounds preferable to me.
It's just that my work is at a pharmacy, and it's so busy there, even my manager gets busy. He's also a pharmacist (I'm a pharmacist assistant, I mostly work at our storage).
It's mostly busy there, with many customers, so mostly there's no time.

What I can do now is further improve my work, and wait for the opportunity to ask him. While teaching me something minor about the storage, he mentioned I need to overthink my work. I'll give it a go, I think tomorrow would be a good time since there are no deliveries which can take up an entire day.

Keep us posted on how it goes