The Secondary Conditions Most Veterans Never Claim

Most veterans know the drill on their primary claim. You served, something got broken, you filed for it, and you got a rating. But here's what the VA doesn't hand you in a pamphlet: your service-connected conditions often cause OTHER conditions down the road — and those secondary conditions can be service-connected too. The problem is that most veterans never file for them. They either don't know secondary claims exist, or they assume the connection is too obvious to need spelling out (spoiler: the VA needs it spelled out).

This is where a lot of money and a lot of care gets left on the table. A veteran rated at 40% for a bad back who never files for the depression that came from living with chronic pain. A knee-injury vet who never connects the dots when the other knee starts failing from overcompensation. A PTSD-rated vet whose sleep apnea gets denied because nobody submitted a nexus opinion tying it to the psych condition.

Let's walk through the secondary conditions that get missed most often, why they get missed, and how to actually get them service-connected.

What Counts as a Secondary Condition

Under 38 CFR § 3.310(a), a disability that is proximately due to — or the result of — a service-connected condition can itself be service-connected. Under § 3.310(b), a non-service-connected condition that is AGGRAVATED (made worse) by a service-connected condition can also be granted secondary service connection, per the Allen v. Brown line of cases — but the compensation covers only the measured increase in severity above the condition’s pre-aggravation baseline, not the whole condition.

Either pathway needs three things:

A currently diagnosed condition
An already-service-connected condition
A medical nexus opinion linking the two — either proximate cause OR aggravation

That third element is where most claims fall apart. A veteran writes on their application, "I got depressed after my back was rated because I can't work like I used to." That's not a nexus opinion. That's a personal statement. The VA needs a medical professional to say, in writing, that the depression is at least as likely as not caused or aggravated by the back condition. Under § 3.102, once the evidence reaches that 50/50 threshold, VA resolves reasonable doubt in the veteran's favor — but the medical opinion has to get you to the threshold in the first place.

Mental Health Conditions Secondary to Physical Injuries

This is the biggest missed category, hands down.

Chronic pain is exhausting. Living with a bad back, ruined knees, migraines, or nerve damage grinds people down. Depression and anxiety are extremely common downstream consequences — the medical literature on chronic-pain-induced depression is thick, and VA examiners generally accept the connection when a proper opinion is submitted.

But veterans routinely don't file. Some think they'd be "double-dipping." Others don't want to admit they're struggling mentally. Some just don't know the pathway exists.

Mental health ratings under 38 CFR § 4.130 step at 0%, 10%, 30%, 50%, 70%, or 100% — the schedule skips the in-between numbers. Even a 30% secondary rating for depression can meaningfully change a veteran's combined evaluation, especially when combined with existing ratings using the § 4.25 combined-ratings math. And a 50% or 70% rating changes things significantly.

At Augustus Miles, our VA-accredited attorneys see this pattern on almost every case we work — a veteran who's been carrying an untreated depression or anxiety condition for years, never realizing it could be tied back to the physical condition VA already recognizes.

Sleep Apnea Secondary to PTSD, Rhinitis, or Weight Gain

Sleep apnea is one of the most-litigated secondary claims at the Board of Veterans' Appeals for a reason: the science supports several causal pathways, but VA raters often deny without a solid nexus opinion in the file.

Common secondary theories:

Sleep apnea secondary to PTSD. Multiple peer-reviewed studies link PTSD to obstructive sleep apnea through mechanisms including sleep fragmentation, hyperarousal, and disrupted REM architecture.
Sleep apnea secondary to service-connected rhinitis or sinusitis. Chronic nasal obstruction is a recognized OSA risk factor.
Sleep apnea aggravated by weight gain caused by a service-connected condition. If a service-connected knee or back injury led to inactivity and weight gain, and the weight gain worsened pre-existing sleep apnea, § 3.310(b) aggravation may apply.

A CPAP-required sleep apnea diagnosis is rated 50% under Diagnostic Code 6847. That's a substantial rating that a lot of veterans qualify for on secondary grounds but never pursue.

Radiculopathy and Neuropathy Secondary to Spine Conditions

If your back or neck is service-connected and you have numbness, tingling, burning, or weakness radiating into your arms or legs, that's not just "part of the back rating." Under § 4.14, VA can't rate the same impairment twice — but distinct manifestations of a single condition get SEPARATE ratings under the Esteban v. Brown framework.

Radiculopathy of each affected extremity gets its own rating under the peripheral nerve diagnostic codes. Bilateral involvement can also trigger the bilateral factor under § 4.26, which combines the paired-extremity ratings as usual and then adds 10 percent of that combined value — not a flat 10 points — before the adjusted figure enters the final § 4.25 math.

This one gets missed constantly. A veteran with a 20% back rating and shooting pain down both legs might be sitting on two or three additional ratable disabilities they've never filed for.

Cardiovascular Disease Secondary to PTSD or Sleep Apnea

The research linking chronic PTSD to cardiovascular disease has strengthened significantly in the last decade. Hypertension, ischemic heart disease, and other cardiovascular conditions can be secondary to a service-connected mental health condition when a physician provides an opinion connecting them.

Sleep apnea is also a recognized independent risk factor for hypertension and heart disease. Chain-linking secondary claims (service → PTSD → sleep apnea → hypertension) is aggressive but legitimate — each link needs its own nexus opinion, but the chain holds if the medical evidence supports it.

GERD and GI Conditions Secondary to Medications

Here's a pathway veterans almost never think about: the MEDICATIONS you take for a service-connected condition can cause new problems, and those new problems can be service-connected.

NSAIDs prescribed for chronic pain are well-documented causes of gastritis and peptic ulcer disease, and are also a recognized risk factor for GERD. SSRIs and other psychiatric medications have known GI side effects. Long-term steroid use has its own list.

If a doctor prescribed the medication for your service-connected condition and a new condition developed as a side effect, § 3.310(a) proximate-cause secondary service connection may apply. The nexus opinion needs to identify the specific medication, the mechanism of injury, and the causal link.

Augustus Miles handles this exact kind of layered secondary analysis. Our attorneys know what evidence VA examiners actually want to see.

Erectile Dysfunction Secondary to Mental Health, Medications, or Vascular Disease

Erectile dysfunction is a common secondary condition tied to PTSD, depression, diabetes, cardiovascular disease, and the medications used to treat all of the above. It's underclaimed because veterans don't want to talk about it.

The rating itself is often 0% under Diagnostic Code 7522, BUT — and this is the important part — a 0% ED rating typically qualifies the veteran for Special Monthly Compensation under SMC-K for loss of use of a creative organ. SMC-K is a flat monthly add-on payable in addition to your basic compensation, and in many cases alongside other SMC levels under § 3.350(a) — though statutory ceilings can cap the combined total. It's not a huge amount, but over the course of a veteran's life it adds up substantially, and it's paid tax-free.

Migraines Secondary to TBI, Neck Injuries, or Mental Health

Migraines are frequently secondary to service-connected traumatic brain injury, cervical spine conditions, or mental health disorders. Rated under DC 8100, migraines can go up to 50% — but that top tier requires very frequent, completely prostrating, and prolonged attacks productive of severe economic inadaptability. The 30% tier is characteristic prostrating attacks averaging about once a month, so the 50% bar is meaningfully higher than just having prostrating attacks.

The TBI-secondary pathway under § 3.310(d) has specific severity and timeline requirements for certain conditions (parkinsonism, seizures, dementias, depression, hormone deficiency get the presumption if the TBI severity and timeline gates are met). Migraines aren't on the presumptive list, but standard § 3.310(a) proximate-cause secondary applies with a nexus opinion.

How to Actually File a Secondary Claim

Here's the playbook that works:

Identify the primary service-connected condition. You need this already granted; secondary claims layer on top.
Get a current diagnosis of the secondary condition. VA needs a diagnosed condition, not just symptoms.
Get a nexus opinion. This is the load-bearing element. A private physician's opinion, a treating VA provider's opinion, or an independent medical opinion (IMO) — whatever it takes to get a doctor to say "at least as likely as not" caused OR aggravated by the service-connected condition. For aggravation claims under § 3.310(b), the opinion also needs to establish a baseline: how bad was the non-SC condition BEFORE the aggravation began? Without a baseline, VA can't measure the increase.
File the claim. Use VA Form 21-526EZ. If you're not ready to file the full claim yet but want to protect your effective date, an Intent to File under 38 CFR § 3.155(b) preserves your effective date — but ONLY if you file a complete claim within one year. If you don't, the ITF lapses and the protected date is lost.
Attend the C&P exam. VA will usually order one. Be honest and specific about how the secondary condition affects your daily life.

Why So Many Secondary Claims Fail

The #1 reason: missing or weak nexus opinions. A veteran writes their theory on the application, VA orders a C&P exam, the examiner writes "less likely than not" because the veteran didn't come in with any supporting medical opinion, and the claim gets denied.

The fix is to build the nexus BEFORE VA schedules the C&P — not after. When a veteran walks into a C&P with a well-reasoned private nexus opinion already in the record, the examiner has to engage with it. When there's nothing in the file, the examiner defaults to their own opinion, and that opinion often doesn't favor the veteran.

At Augustus Miles, this is what our VA-accredited attorneys do every day. We help veterans identify secondary conditions they didn't realize were on the table, work with medical experts to develop the nexus evidence, and file claims that put the strongest possible evidence in front of VA.

The Combined-Ratings Reality

One thing to understand: adding a secondary rating doesn't just add dollars — it changes your combined evaluation under § 4.25, which uses a whole-body-remaining formula rather than simple addition. A veteran at 70% who adds a 30% secondary condition doesn't jump to 100%. The math combines to 79, which rounds to 80%.

But those combined-rating increases matter. Moving from 70% to 80% at COLA 2026 rates takes a veteran alone from $1,808.45 to $2,102.15/month — a meaningful monthly increase, tax-free. Rates shown are 2026 figures; check va.gov for current amounts.

And secondary conditions can also be the key that unlocks TDIU under § 4.16, or that pushes a veteran's rating structure into SMC territory under § 3.350.

The Bottom Line

If you have a service-connected condition and you've developed anything downstream from it — mental, physical, medication-related, or otherwise — it's worth asking whether a secondary claim is on the table. The claims most veterans never file are the ones that could most meaningfully change their monthly compensation and their access to VA care.

If you're not sure where to start, Augustus Miles can help. Our VA-accredited attorneys work on a contingency basis — you pay nothing upfront, and only pay if the claim succeeds. Our support team is made up of veterans who've been through the process themselves, many of whom were former clients before they joined the team.

Frequently Asked Questions

What's the difference between a primary and secondary VA claim?

A primary claim seeks service connection for a condition caused by service itself (an injury or disease incurred or aggravated during active duty). A secondary claim under 38 CFR § 3.310 seeks service connection for a NEW condition that was caused or aggravated by an already-service-connected condition. The already-service-connected condition is the predicate; the secondary claim layers on top.

Do I need a private doctor's opinion, or can I rely on the VA C&P examiner?

Technically you can rely on the VA C&P examiner, but in practice you shouldn't. If nothing in your file supports the secondary connection when the examiner sits down, the default opinion tends to run against the veteran. Bringing a well-reasoned private nexus opinion into the record before the C&P is scheduled dramatically improves your odds. The examiner has to actually engage with existing medical evidence rather than starting from scratch.

Will filing a secondary claim put my existing rating at risk?

Filing a secondary claim does not automatically trigger a review of your existing rating. VA can only reduce a rating that's already in place if specific standards under 38 CFR § 3.344 (5+ year stabilization), § 3.343 (total ratings), and the procedural protections in § 3.105(e) and (i) are met. Ratings in effect 20+ years are protected under § 3.951(b) from any reduction except for fraud. A well-supported secondary claim rarely leads to a review of an unrelated primary rating.

How does Augustus Miles help with secondary condition claims?

Augustus Miles has VA-accredited attorneys on staff who specialize in identifying secondary conditions veterans didn't realize were claimable, developing the medical nexus evidence VA actually looks for, and filing claims built to survive C&P scrutiny. You pay nothing upfront — the attorneys work on a contingency basis. Our support team is made up of veterans, many of whom started as clients.

Can I file multiple secondary claims at the same time?

Yes. There's no limit on the number of secondary claims you can file, and there's no rule saying they have to be filed one at a time. Veterans commonly file for depression, sleep apnea, radiculopathy, and GERD together when the underlying medical picture supports it. Each claim needs its own diagnosis and its own nexus opinion, but they can all be pursued in parallel.