If the first thing you do when you get home is take off your bra, then chances are you have an ill fitting bra that is causing you pain either in the neck, back, and or shoulders.
Most women are currently wearing bras that don't fit well. If you have grooves in your shoulders from the straps your bra band isn't being very supportive. In fact Most of the support should be coming from the bra band not the straps. If you are experiencing "gapping" or "spillage" the cup type or size is not ideal.
To figure out the size range that you should be wearing I recommend seeing a tailor to be measured and fitted. But if you don't have the time to do that you can take your measurements at home.
The Cup/Band Equation yes this is a thing
To measure at home, you’ll need two measurements: around your back and under your bust for your band size, and around your back over fullest portion of your breast for your cup size. You’ll then subtract the difference. For example, if your bust measures 35 inches and your under-bust (or rib cage) 32 inches, you’ll be a 32C because 35 minus 32 equals 3, and that number corresponds to the letter “C” in the alphabet. If you are greater than 4 the scale continues with 4 =D,5= DD/E,6=DDD/F and so forth. That being said every brand is slightly different in fit just like a pair of jeans you should be prepared to try them on for find the right fit.
The Ideal Fit
The breast should feel supported and not smashed or pinched.
The band closure clasp should be in the middle- there is a range of clasp in each band to allow for adjustment through the day or through the month as our breast can become "fuller" as hormones change through the month or more sensitive to pressure.
The band should never ride up.
You feel supported even when the straps are not in place- ( the mark of a well made bra)
The Straps should allow for a finger to slip under without difficulty-meaning they are snug but allow for movement of your shoulder and clavicle through the day.
Of course fit is a personal preference but if you keep these tips in mind you may save yourself from neck, back , and shoulder pain in the future.