A diagnosis prediction market! I know I should "really see a specialist" "should not take this as a substitute for expert advice" etc. but (1) urologists and endocrinologists just keep doing blood tests and sending me back without a diagnosis because they can't think of what tests to do and (2) I don't think this has been tried, should be fun. Should any legal issues arise: I forfeit all rights, I would never try to sue the hand that feeds me information (even if wrong), and I will not attempt to get any treatment/surgery without a proper medical diagnosis.

Resolution: I'll take tests based on the linked recommendation market (Tests to diagnose my erectile dysfunction: Conditional Market). Based on what doctors have said to me so far (e.g. "what would we even look for in an MRI?") I think I should be better able to push for tests if I have a more precise idea of what to look for, and would also be more willing to buy private healthcare if I know what to do with it exactly. If I'm unable to have something diagnosed, it will resolve N/A.

Anyone can add answers; naturally it is better to add answers that can be more directly tested because they won't resolve N/A. You can ask for additional information: I think it makes sense to ask for information privately to insider trade (and I'll make it public once you're done trading on said information).

Case details

TL;DR: This is how I summarized the info to ChatGPT (with @EliezerYudkowsky's preface):

24-year-old male with Erectile Dysfunction. Specifically, two sudden overnight drops in libido at age 18 and 20, and consistently low since. Has Death Grip, i.e. inability to orgasm during oral sex. Has morning erections and throughout the night, but weaker than usual.

Healthy weight, no history of smoking/drugs/steroids/hormonal treatments. Blood tests are almost entirely normal, and have ruled out Diabetes and Hypercalcemia.

Only significant results: somewhat low testosterone (14 nmol/L, healthy range is 10-30 nmol/L), slightly high TSH (5.2 mIU/L, healthy range is 0.3-4.2 mIU/L), low FSH (1.1 mIU/L, healthy range is 0.3-4.2 mIU/L).

Vitamin D was very low when symptoms first began but immediately became normal upon supplementation. All other results are normal: Cortisol, Prolactin, SHBG, LH, Free T3/T4, Total T3/T4.

And ChatGPT's response ([...] indicates a paragraph inserted from another ChatGPT run):

[...] Given the relevant lab results within the provided case, our patient’s results indicate a potential disorder in the hypothalamic-pituitary-thyroid (HPT) and hypothalamic-pituitary-gonadal (HPG) axis. These axes are integral in managing both thyroid and sexual health, correspondingly.

From the physical examination and blood test results, this patient's symptoms could indicate Hypogonadotropic Hypogonadism (HH), a condition where there is a lack of production of adequate sex hormones due to a problem with the pituitary gland or hypothalamus. The somewhat low testosterone combined with low follicle-stimulating hormone (FSH) values might suggest this, as both testosterone and FSH are crucial for maintaining sexual function and libido.

The slightly elevated thyroid-stimulating hormone (TSH) may imply a mild thyroid dysfunction that could have contributed to erectile dysfunction; however, thyroid hormones Total T3/T4 and Free T3/T4 appear in the normal range, which does not solidly support this assumption.

To further investigate, an MRI of the brain focusing on the pituitary could provide useful information. If there's a tumor or structural abnormality of the pituitary or hypothalamus, it could lead to decreased secretion of gonadotropins, causing HH.

Another useful test would be a test of gonadotropin-releasing hormone (GnRH). If the patient's pituitary responds with a significant release of LH and FSH, then the problem likely lies in the hypothalamus (secondary HH). If there's no significant release, the problem more likely lies in the pituitary (primary HH).

[...] According to the TRH stimulation test, if TSH levels rise significantly following administration, this supports the diagnosis of subclinical hypothyroidism.

In this case study, and given the listed data, if the further tests were run, I would predict an MRI showing no gross abnormalities in the pituitary gland or hypothalamus, hence ruling out structural issues as the cause of the symptoms. The GnRH test might show no significant release, indicating primary HH. This would suggest the mild low testosterone and low FSH is due to pituitary malfunction.

Patient description: 24-year old male (heterosexual, cis). Healthy body weight BMI=22 (used to be overweight BMI=27 until age ~21), body fat=19%. Have not taken any drugs (including alcohol) or steroids/hormones, diet has consistently been healthy and rich in all the things online blogs say are good for testosterone.

Symptoms history:

• Sudden overnight drop in libido at age ~17/18. Symptoms:

  • Don't get constant erections throughout the day

  • Hard to get erections while standing

  • Still get morning erections & throughout the night

• Another sudden overnight drop in libido in Jan 2020 (age 20). Symptoms:

  • Can't get erections through "imagination" alone: need visual + physical stimulation to my penis. Often cannot get an erection even with a woman, but can't sustain it for sex

  • Cialis helps a lot, but erections still not as strong as before 2020

  • "Death grip" syndrome even with cialis: can't orgasm/ejaculate to fellatio (real sex works, though with time)

  • Still get morning erections & throughout the night, but weaker

  • Symptoms much worse at night

• Doctor recommended taking viagra 100mg daily for 2-3 months if it may be psychogenic. I took viagra 100mg for 6 months, and cialis 20mg (max dose) for over a year but it stops working once I'm off it.

Tests etc.

• Took some comprehensive blood tests between 2020-2023; Stuff I've measured: Testosterone, Cortisol, Prolactin, SHBG, FSH, LH, TSH, Free/Total T3/T4, Blood Sugar, HbA1C, Calcium, Adjusted Calcium, Lipid Profile, Liver Profile, eGFR, Prostate Specific Antigen, Vitamins, Electrolytes, Blood Proteins (Total Protein, Albumin, Bilirubin, Globulin), Erythrocyte sedimentation rate, Alkaline Phosphatase, Creatinine, Urea.

• Everything normal (in particular, Diabetes & Hypercalcemia ruled out), except:

  • Testosterone: 9.0 nmol/L - May 2020 (range: 10-30) [!!]

  • Testosterone: 13.0 nmol/L - Sep 2021

  • Testosterone: 15.0 nmol/L - Jun 2022

  • TSH: 2.0 milliunit/L - May 2020 (range: 0.3-4.2)

  • TSH: 5.2 milliunit/L - May 2023 [!!]

  • FSH: 1.1 unit/L - May 2020 (range: 1.7-8) [!!]

  • FSH: 1.5 unit/L - Sep 2021 [!!]

  • Prolactin: 220 milliunit/L - May 2020 (range: 60-300)

  • Prolactin: 210 milliunit/L - Sep 2021

  • Vitamin D: <10.0 nmol/L - May 2020 (range: 70-150) [!!] — normal after supplementation in the 2021 and 2023 tests

• Physical examination of penis & testes by urologist: no lumps. Veins in penis look normal.

• Note on testosterone: All the tests were done in the morning (except Jun 2022, which was done around 3pm) since clinics close in the evening. It's possible levels were much lower in the night when symptoms are worst. With that said my levels would probably have increased since 2022 from weightlifting (e.g. my facial hair growth is much denser/less patchy now) but symptoms haven't improved.