Karolina Widerström was the daughter of the gymnastic teacher and veterinarian Otto Fredrik Widerström and Olivia Erika Dillén. The family moved to Stockholm in 1873.
Education
Women were officially admitted to the universities in Sweden in 1870. Her father wished for her to be a gymnastic teacher like himself. In 1873–1875, Karolina Widerström was a student at the Royal Central Gymnastics Institute, and in 1875–1877, she was the assistant to Professor Branting. She was also active as a medical gymnast. In 1879, she received her exam at Wallinska skolan and in 1880 her exam in medical philosophy at the university at Uppsala. In May 1884, she received her medical exam at the Karolinska Institutet in Stockholm.
Medical career
Widerström wanted women and girls to know more about their own bodies, to dress more healthily, and to receive the same rights and possibilities as men. She was especially active within gynecology and women's health. Her best-known work within her field was Kvinnohygien, which was first published in 1899, and reprinted in seven editions until 1932.
Activism
Concerned for women's health issued, she was a strong supporter of the Swedish Dress Reform Association and a vocal force in writing medical articles advocating against tight laced corsets, which at this point in time was a serious health issue. From about 1900, Widerström was active in the struggle to abolish the so-called reglementation of prostitutes, that is to say the forced registration and regular examination for venereal diseases of prostitutes, a system highly debated among women's rights activists at the time, which organized in the Svenska Federationen to oppose it.
Political engagement
Karolina Widström was elected to the Stockholm city council in 1912 for the liberals, where she served until 1915. She was elected chairwoman of the Swedish Society for Woman Suffrage in 1918, one year before the women suffrage was granted in Sweden in 1919, and became its last chairwoman when she stepped down after the organisation was dissolved in 1921, when the purpose of the organisation was fulfilled and both genders exercised the right to vote in the 1921 election.