Thousands of employees at CVS Health Corp. and Walgreens Boots Alliance's U.S. pharmacies are planning a three-day walkout starting Monday, in an attempt to get the companies to improve working conditions and recruit more people, among other issues.

This walkout, which they are calling "Pharmageddon," is the third major strike by pharmacists in a little over one month. In September, some staff from CVS stores in Kansas City went on a two-day strike, while there was one by Walgreens store employees earlier this month.

"Some of these stores are so grossly understaffed at the moment and just bogged down with not only prescriptions but the amount of immunization appointments and walk-ins that they're expected to do," Shane Jerominski, a former Walgreens pharmacist and one of the organizers of the walkout, told Reuters.

Jerominski said the organizers were also seeking better pay and more consistent hours for technicians, who locate, dispense, pack, and label prescribed medication for patients under the supervision of pharmacists.

A spokesperson for CVS said its leaders were connected with their pharmacists to directly address concerns and engaged in a "continuous two-way dialog."

Walgreens said the company has taken steps to help its pharmacy teams "concentrate on providing optimal patient care."

"Our ongoing efforts are focused on how we recruit, retain, and reward our pharmacy staff," a spokesperson for Walgreens told Reuters, adding that they have also centralized some operations to reduce pharmacists' workload.

The company earlier this month said it opened its 11th micro fulfillment center, which are centralized units that fill prescriptions, allowing its "staff to spend more time with customers" to offer other health-related products and services.

The walkouts are part of the larger trend of labor unrest in several industries, including strikes by autoworkers, writers and actors, as well as the largest recorded medical worker walkout by employees of not-for-profit hospital system Kaiser Permanente earlier this month.