Teachers lives are being made "hell on earth", especially by abusive schoolboys.

Friday was World Teachers' Day and Unesco called on societies to "take a stand for teachers" because the profession was losing its status.

There are teacher shortages around the world, especially in sub-Saharan Africa. According to the UN Educational, Cultural and Scientific Organisation, there is a deficit of 1.8million teachers in the region.

And those who are teaching have to grapple with numerous problems, including ill-disciplined pupils, lack of parental support and over-age pupils, according the National Professional Teachers' Organisation of SA.

Most of the time teachers were subjected to "malicious" behaviour by a small group of pupils, usually boys, Naptosa president Ezra Ramasehla said.

Boys - many of whom are in the care of their grandparents - often smoke dagga in school toilets, abuse drugs and alcohol, and are bullies who bunk classes to roam the school grounds, he said.

"The sum total of all these shenanigans makes the lives of teachers a living hell at schools because they cannot concentrate on their core duties and functions but on sideline duties that could have been performed by support staff such as psychologists and social workers, even parents," Ramasehla said.

Teachers often received "zero" support from their pupils' parents or guardians.

"One teacher told how parents could easily attend a political rally in their droves, but failed to attend a school parents' meeting," he said.