PSA Watch: PSA velocity & doubling time tracker

About this app

What PSA Watch does

You're on active surveillance for prostate cancer, which means one thing over and over for years: another blood draw, another PSA number, another wait. And every time it ticks up a tenth, the same question hits — is this real progression, or just noise? Apple Health can store the number, but it computes none of the math that actually informs that question. PSA Watch does. Log each result — date, PSA in ng/mL, and optionally your free/total ratio and prostate volume — and PSA Watch plots the whole history on one clean trend chart with the common reference band drawn in. Then it runs the surveillance math that a decision to re-biopsy actually leans on: PSA velocity in ng/mL/yr from a linear fit of your results, doubling time in months from a regression on the natural log of your PSA, and PSA density (PSA divided by prostate volume) whenever you've entered a volume from an MRI or ultrasound report. The centerpiece is the plain-language readout: “Real progression, or noise?” PSA Watch checks your velocity against the commonly cited 0.75 ng/mL/yr and your doubling time against the roughly 36-month figure that tends to draw a closer look, and tells you in a sentence whether your trend looks consistent with normal variation or is a pattern worth raising with your urologist. It is written as context for a conversation — never as a diagnosis. Round it out with an appointment schedule (next PSA draw, MRI, biopsy, urology visit) with local reminders, and a clean shareable report you can hand to your doctor or text to your spouse. Everything stays on your phone: no account, no server, no upload of your health history. PSA Watch is a tracking and reference tool, not a diagnostic device. Every decision about biopsy, imaging or treatment belongs with your urologist. • Trend chart of every PSA result with a reference threshold band • PSA velocity (ng/mL/yr) from a linear fit of your results • Doubling time (months) via regression on ln(PSA), guarded against flat or falling trends • PSA density from prostate volume, and free/total ratio tracking • “Real progression or noise?” plain-language readout against common thresholds • Appointment schedule with reminders for PSA draws, MRI and biopsy • Shareable summary report for your appointment • 100 percent offline — your PSA history never leaves your phone