Difference between Painful and Achy

PAINFUL vs ACHY: ADJECTIVE

Causing physical or psychological pain
Causing physical discomfort
Exceptionally bad or displeasing
Full of or giving pain.
Causing mental anguish or suffering.
Distressing or embarrassing.
Requiring care and labor; difficult or irksome.
Marked by or requiring great care and diligence.
Full of pain; causing uneasiness or distress, either physical or mental; afflictive; disquieting; distressing.
Requiring labor or toil; difficult; executed with laborious effort.
Painstaking; careful; industrious.
Causing misery or pain or distress

They can be very painful"
Synonyms and Racking, agonizing, tormenting, torturing, excruciating, arduous, severe, grievous, trying, afflictive.
Painstaking; industrious; busy; careful; laborious; hard-working.
That requires or necessitates labor, exertion, care, or attention; troublesome; difficult; toilsome.
That gives or is characterized by pain; of a nature to pain, render uneasy, or inflict suffering, whether bodily or mental; distressing: as, a painful operation in surgery; a painful effort; a painful subject.

Irritating, Awful, Agonized, Dreadful, Poignant, Uncomfortable, Bitter, Terrible, Harrowing, Agonizing, Unpleasant, Torturous, Traumatic, Wrenching, Excruciating

Nauseous, Stomachache, Itchy, Tiredness, Numbness, Pain, Arthritic, Charley horse, Backache, Crampy, Bruised, Throbbing, Sore, Painful, Aching

Irritating, Awful, Agonized, Dreadful, Poignant, Uncomfortable, Bitter, Terrible, Harrowing, Agonizing, Unpleasant, Torturous, Traumatic, Wrenching, Excruciating

Nauseous, Stomachache, Itchy, Tiredness, Numbness, Pain, Arthritic, Charley horse, Backache, Crampy, Bruised, Throbbing, Sore, Painful, Aching

This may be painful, but is nonetheless beneficial.
Arthritis of the hand can be very painful.
This buildup of fluid can be very painful.
Sanctions are more painful when they cause more damage than expected, or when a period of growing prosperity gives way to a painful decline.
Produce Abscesses produce painful swelling at the anus as well as painful defecation.
If patient is bearing weight there is a painful limp to be observed as walking is painful.
When hands are swollen and painful from arthritis, cold packs can numb the painful joints and reduce swelling.
Maria, are the suffering in Purgatory more painful than the most painful sufferings on earth?
The symptoms of endometriosis include painful menstrual cramps, painful intercourse, diarrhea, constipation, and nausea.
This condition can cause painful bleeding, cramps and painful intercourse.