Know Your Body
I recently had a crazy blood clot and hormonal birth control is not ideal for me anymore. My pal, Kelly, a pelvic floor physical therapist, recommended The Fifth Vital Sign: Master Your Cycles and Optimize Your Fertility to me. I value any work that helps people reclaim agency over their bodies, challenge medical gaslighting, and understand the intricate connection between hormonal health and sexuality. Lisa Hendrickson-Jack’s book argues that the menstrual cycle should be considered a crucial indicator of overall health. The book offers an extensive, evidence-informed look at fertility awareness and menstrual tracking as tools of empowerment, particularly for people who have been underserved or dismissed by conventional medicine.
From a therapeutic standpoint, this emphasis on body literacy is deeply affirming. Many of my clients struggle with shame, confusion, or a sense of disconnection from their cycles. These feelings are often rooted in years of inadequate sex education and patriarchal messaging about menstruation. Hendrickson-Jack’s detailed explanations of hormonal rhythms, cervical mucus, and basal body temperature tracking can help normalize these processes and foster a healthier sense of embodiment. Her work aligns well with trauma-informed and pleasure-centered approaches to sexuality, which prioritize curiosity and self-knowledge over control or perfectionism.
However, The Fifth Vital Sign can also feel overwhelming and, at times, overly rigid. Its tone occasionally veers toward medical absolutism—suggesting that if readers simply master fertility awareness, they can optimize their health and avoid most reproductive pitfalls. For clients with complex health conditions, trauma histories, or irregular cycles, this can unintentionally replicate the same sense of self-blame that the book seeks to dismantle. She also has an explicit distrust of hormonal contraception that, while understandable given historical medical negligence, risks alienating readers for whom these methods are empowering or necessary. A more nuanced discussion of choice and bodily autonomy would have strengthened the book’s message.
The Fifth Vital Sign is an important, passionate contribution to reproductive health literacy, one that challenges readers to see menstruation not as a burden, but as vital communication from the body. As a sex therapist, I would recommend it selectively: it’s a valuable tool for those ready to dive deep into charting and hormonal health.
It’s a book that not only empowers, but also reminds us that true sexual wellness comes not only from mastering our biology, but from embracing the full, messy humanity that comes with it.
