What it is
If you''re already service-connected for one condition, and that condition caused or made another condition worse, the new condition is also service-connected under 38 CFR § 3.310. You don''t need to prove the second condition started in service — you just need to prove the first condition caused it.
Common high-value secondary chains
- Sleep apnea secondary to PTSD — The most-claimed secondary in the VA system. Documented link via weight gain, medication side effects, and disrupted sleep architecture.
- Depression / anxiety secondary to chronic pain — Living with constant pain has a documented mental-health impact.
- GERD secondary to PTSD or its medications — SSRIs and chronic stress both contribute.
- Hypertension secondary to PTSD — Recognized link via chronic sympathetic nervous system activation.
- Erectile dysfunction secondary to PTSD or SSRIs — Common, often missed. Comes with SMC-K ($138.65/mo additional).
- Radiculopathy secondary to back conditions — Pinched nerve from a service-connected back issue.
- Migraines secondary to TBI — Direct neurological causation.
- Foot conditions secondary to knee or back conditions — Altered gait causes downstream wear.
What you need to file
- Establish the primary — already service-connected and rated.
- Diagnosis of the secondary — current medical record or VA exam noting the new condition.
- Medical nexus opinion linking the secondary to the primary. A private doctor''s "more likely than not" letter is gold.
How to file
- File a new claim on VA Form 21-526EZ, marking it as a secondary condition.
- In the contention, write it explicitly: *"Sleep apnea, secondary to service-connected PTSD."*
- Attach your nexus letter and any treatment records connecting the two.
Aggravation also counts
If your service-connected condition didn''t cause the new condition but made it worse, you can claim the aggravated portion. The VA establishes your "baseline" before the service-connected condition came into play and rates only the additional disability beyond that baseline.
Bottom line
If you have a service-connected condition and a current diagnosis that''s plausibly related, you should be filing a secondary claim. The VA does not connect these dots for you.