Current as of September 28, 2026. General information, not medical advice.
Short answer: A head injury can damage the pituitary, and about a third of people have some pituitary hormone deficiency in the years after a TBI. Nobody screens for it routinely, because the VA and DoD guideline for mild TBI makes no recommendation either way. If your symptoms started after a blast or a concussion, the labs are worth asking for by name.
The overlap that gets missed
Fatigue. Low motivation. Poor sleep. Irritability. Trouble concentrating. Low libido.
That list is the reason this gets missed. It is also the symptom list for post-concussive syndrome, for PTSD, and for depression, which is usually what gets diagnosed.
A VA research team put it plainly: hypopituitarism, and growth hormone deficiency in particular, is associated with symptoms that resemble those of PTSD, including fatigue, anxiety, depression, irritability, insomnia, sexual dysfunction and cognitive deficiencies.
Those conditions are real and common. The problem is that an endocrine cause sitting underneath them rarely gets ruled out, because nobody orders the test.
What the research actually shows
The prevalence work is consistent across two decades.
A 2007 analysis of 19 studies and 1,137 patients found hypopituitarism in 27.5 percent in the chronic phase after TBI, more often after severe injury.
A 2020 analysis of 29 studies and 2,756 patients, all at least a year out, found 32 percent.
A 2024 analysis of 52 studies and 7,367 patients found 33 percent, with growth hormone affected in 18 percent, the gonadal axis in 16 and ACTH in 10.
In veterans specifically, at a VA hospital in Puget Sound, 11 of 26 blast mild-TBI veterans screened abnormal on one or more pituitary axes in one study, and 12 of 39 in another, against 3 of 20 deployment controls. Those researchers recommended routine post-deployment neuroendocrine screening for blast-exposed service members and veterans.
Why your labs do not exist
The VA and DoD clinical practice guideline for post-acute mild TBI, version 3.0 from June 2021, is the document your care runs on.
It does not mention the pituitary. Not once. Hypopituitarism, hypogonadism and testosterone appear zero times each. Neuroendocrine disorders appear three times, all in the section listing research priorities.
So the guideline does not tell anyone to screen you, and it does not tell anyone not to. It classifies the question as an unresolved evidence gap.
The only formal consensus statement on the subject, from 2005, recommends systematic screening of pituitary function for all patients with moderate to severe TBI at risk of deficits. It is not VA policy.
That is the whole explanation for why a man with a documented blast injury and six years of fatigue has never had his LH checked.
What to ask for
Ask by name, in the morning, fasting.
Total testosterone, drawn between 8 and 10am, twice on separate days. LH and FSH, which distinguish a testicular problem from a pituitary one. Prolactin. Thyroid function including free T4 rather than TSH alone, because pituitary problems show up differently. Morning cortisol. IGF-1 as a growth hormone screen.
If total testosterone is very low, under about 150, that is a reason to look specifically at the pituitary, including imaging.
The reason for the full panel rather than testosterone alone: if a head injury damaged the pituitary, testosterone is rarely the only axis affected, and the other ones matter more clinically.
The benefits angle, briefly
If your TBI is service connected, this is worth knowing: the regulations hold hormone deficiency from hypothalamo-pituitary changes to be the result of a service-connected TBI, absent clear evidence otherwise, when it appears within 12 months of a moderate or severe injury. Missing that window does not bar a claim, it just makes it an ordinary one.
We wrote a separate piece on how that works, and on why a standalone low testosterone claim rates zero while the other pituitary axes carry real percentages.
What this does not mean
It does not mean your symptoms are definitely hormonal. Most are not.
It does not mean testosterone treats TBI, PTSD or depression. It does not, and anyone telling you otherwise is selling.
And it does not mean skip the mental health care. If the endocrine workup is clean, you have ruled something out and lost nothing.
Questions people actually ask
Can a TBI cause low testosterone? Yes. Injury to the hypothalamic-pituitary region can impair the hormonal signal to the testes. Roughly a third of TBI patients have some pituitary deficiency in follow-up studies.
Why has nobody tested me? The VA and DoD mild TBI guideline makes no recommendation on endocrine screening, listing it as a research gap.
Which labs should I ask for? Morning fasting total testosterone twice, LH, FSH, prolactin, free T4, morning cortisol and IGF-1.
Does blast exposure count? VA research on blast mild TBI found abnormal pituitary screening in 31 to 42 percent of those veterans, against 15 percent of controls.
Will treating this fix my PTSD? No. They can coexist and share symptoms. Testing tells you which parts are which.
Where we fit
We run the full pituitary panel, not testosterone in isolation, and we read it with you. If it points at something outside our lane, we will say so and tell you who to see.
Our clinic is on the Emerald Coast between Eglin and Hurlburt Field, and telemedicine covers 47 states. Discounted pricing for military, law enforcement and first responders.
Request a consultation at hewhealth.com or call (850) 820-8850.
Hew Health, LLC is a private medical practice. We are not affiliated with, endorsed by, or connected to the Department of Veterans Affairs or the Department of Defense. General information as of September 28, 2026, not medical advice. Testosterone is a Schedule III controlled substance approved for men with low testosterone caused by an associated medical condition. It is not a treatment for traumatic brain injury, post-traumatic stress disorder or depression.
Sources: VA/DoD Clinical Practice Guideline for the Management and Rehabilitation of Post-Acute Mild Traumatic Brain Injury, version 3.0, June 2021. Schneider et al., JAMA 2007 (PMID 17895459). Emelifeonwu et al., J Neurotrauma 2020 (PMID 31111791). Systematic review, Neurosurg Rev 2024 (PMID 39527353). Wilkinson et al., Front Neurol 2012 (PMID 22347210). Undurti et al., Front Neurol 2018 (PMID 29515515). Ghigo et al., Brain Inj 2005 (PMID 16195185). 38 CFR 3.310(d).