My dad has been sick for over 20 years (...where to begin, pericarditis, myocarditis, leukaemia, para-protein anaemia and chronic fatigue) and mum has basically been his main carer for that time...this year she (out of the blue) had a hemorrhagic stroke which nearly finished her off - she's recovered remarkably but is still restricted in what she can do or she gets very tired and frustrated.
They've been amazing parents - my mum was restricted in showing love and affection for a long time but (we found out) she had had an abominably awful abusive childhood - my dad rescued her...this last couple of years she's doing her very best to be demonstrative in her love...I adore them both.