What was "Breast Complaint"?

Early medical terminology can be confusing. I've been looking for definitions of some of the diseases my early family had. Some of the names they used could be misleading. For years I was thinking breast complaint must be breast cancer. Four women in the same family died of this, i.e, Polly Forgey, Ellen Forgey, Betsy Forgey, and Rachel Forgey. I was thinking it was hereditary breast cancer. When I googled "died of Breast Complaint" I found several references to tuberculosis. I found a google book called, "Language of Mormon Pioneers." Here is their definition of breast complaint:

According to the Crawford family letters (written in the mid-nineteenth century) a number of Forgey family members suffered from "ague". I had no idea what that referred to? I found out it most likely referred to malaria. It could also have been a fever with symptoms similar to malaria. I remember reading about how diseases I thought were tropical were present in early America. Malaria and Yellow Fever epidemics were common in early America.
Apoplexy also perplexed me. Apoplexy would be referred to as a stroke today.
Before clinical tests were developed the cause of death or disease could only be surmised from previous experience or autopsy, and may not have been accurate. Scholars still debate the causes of some early epidemics.