Hospital pharmacies stayed shut and nurses off work as a three-day warning strike by health workers dragged on.
Mostly federal hospitals and other tertiary health institutions are affected.
The Joint Health Sector Unions, which comprise at least four sets of health workers, and the Assembly of All Healthcare Professionals are protesting "acts of industrial violations, injustice and deprivations."
Dispensing bays, where patients get drugs, at National Hospital stayed shut throughout the day.
Loading bays were empty and few patients loitered the usually busy but empty hospital corridors, crowded by student doctors.
A member of National Association of Nigerian Nurses and Midwives (NANNM is an affiliate of JOHESU) confirmed to Daily Trust that the strike was under way and on full implementation.
The warning strike came after seven days of working grace granted by JOHESU and the Assembly of All Healthcare Professionals ran out this week within which government was to address issues in dispute.
The union said it was agonized when an appraisal meeting between both sides on January 16 showed the health ministry "has virtually not implemented any of the issues in contention".
They criticized government rationale for the position of a surgeon-general.
"The information provided on the need for the post of the Surgeon-General cannot be a compelling factor to waste scarce public funds for an ego trip," said the union in a statement.
They also claimed selective wage increases targeting doctors distorts health care