Common VA Secondary Conditions: The Complete List by Primary Disability

Most veterans think of service connection as a straight line from something that happened in service to a condition today. That is direct service connection under 38 CFR 3.303. Secondary service connection is the second step. The rule is 38 CFR 3.310(a) says a disability "which is proximately due to or the result of a service-connected disease or injury shall be service connected." The chain runs from service, to your rated condition, to the new one.

There are 2 ways in:

1. Causation, 3.310(a). The service-connected condition caused the new one. A service-connected knee injury leads to arthritis in that knee. Service-connected high blood pressure leads to heart disease. Both are VA's own examples of a secondary claim.
2. Aggravation, 3.310(b). You already had the condition for reasons unrelated to service, and a service-connected condition made it worse. VA compensates the added severity, minus any worsening from the natural progress of the disease. This rule comes from the Court of Appeals for Veterans Claims in Allen v. Brown, 7 Vet. App. 439 (1995). It carries 1 trap: VA will not concede aggravation unless medical evidence shows the baseline severity before the aggravation began.

Either way, VA looks for 3 things: a current diagnosis of the secondary condition, an existing service-connected primary condition, and a medical opinion linking the 2. Our guide to establishing a secondary connection walks through the process step by step. This page is about which conditions the link most often applies to.

Watch out: The primary condition must already be service-connected, or claimed at the same time. A secondary claim built on a condition VA has denied goes nowhere until the primary is granted.

VA does not publish a ranked list of secondary grants. The list below reflects the pairings that appear most often in Board of Veterans' Appeals decisions and in the rating schedule itself, limited to links with solid medical support.

Source: 38 CFR Part 4 diagnostic codes and 38 CFR 3.350, current as of September 2026; pairings reflect common Board decisions, not a VA statistic.

Each one is rated on its own criteria. The rating schedule guide explains how to read a diagnostic code. What you receive depends on the severity your evidence shows, not on the fact that the condition is secondary.

PTSD, anxiety disorders and depression are rated under a single General Rating Formula for Mental Disorders in 38 CFR 4.130, with levels of 0, 10, 30, 50, 70 and 100. Two things follow from that.

First, a second mental-health diagnosis usually does not get its own rating. If PTSD leads to major depressive disorder, VA rates the combined picture under a single code, because the formula measures overall occupational and social impairment. Claiming depression secondary to PTSD can still matter: it documents worsening and can support a higher level under the same formula.

Second, the physical conditions that follow PTSD are rated separately, and those are the ones that change your combined rating. The links with the strongest medical support:

• Sleep disturbance and nightmares. Part of the PTSD picture; rated inside the mental-health formula unless a separate sleep disorder is diagnosed.
• Substance use disorders. Alcohol or drug use that develops as a way of coping with a service-connected mental-health condition can be service-connected as secondary. Substance use on its own, without that link, cannot.
• GERD and irritable bowel symptoms. Chronic stress and the medications used to treat PTSD both affect the gut.
• Hypertension. The association between PTSD and high blood pressure is documented in the medical literature. VA does not presume it, so the grants in this area rest on a nexus opinion that cites that literature.
• Erectile dysfunction. Most often through SSRI and SNRI antidepressants (selective serotonin and serotonin-norepinephrine reuptake inhibitors), whose sexual side effects are well documented. Compensated as SMC-K rather than a percentage.
• Obstructive sleep apnea. Frequently claimed, and frequently denied. PTSD does not cause the airway to collapse. The medical chain usually runs through weight gain from medication or inactivity, or aggravation of existing apnea by disrupted sleep. What the grants in this area have in common is a nexus opinion that names that mechanism; a vague opinion does not.

The medical nexus letters guide shows what a specific opinion looks like.

Orthopedic conditions produce secondary claims in 2 directions: nerves and the rest of the body's mechanics.

Nerve conditions. A lumbar spine injury that compresses a nerve root causes radiculopathy: pain, numbness or weakness running into a leg. VA rates it separately from the spine under the nerve codes in 38 CFR 4.124a, most often DC 8520 for the sciatic nerve, with levels from mild incomplete paralysis to complete paralysis. Cervical spine injuries do the same to the arms. Note (1) to the spine formula in 38 CFR 4.71a says to evaluate "associated objective neurologic abnormalities" separately. That makes this 1 of the most reliable secondary grants there is, provided an exam or electromyography (EMG) test documents it.

Altered gait. When one knee, hip, ankle or foot hurts, you shift weight to the other side. Over years that can produce arthritis or instability in the opposite knee or hip, or low back pain. VA grants these claims regularly. What they need is a medical opinion that the gait change caused or aggravated the new problem, not only that both exist.

Chronic pain and mental health. Depression and anxiety secondary to chronic pain is one of the best-supported links in medicine and one of the most common secondary mental-health grants. It is rated under the 4.130 formula.

Erectile dysfunction and bladder or bowel problems can follow lumbar spine injuries that affect the nerves of the pelvis. Bladder and bowel impairment are rated separately; erectile dysfunction is SMC-K.

Weight gain and its consequences. A veteran who cannot exercise because of a service-connected orthopedic condition may gain weight, and weight gain drives sleep apnea, diabetes and hypertension. Obesity itself is not a rated disability, so the claim has to show each link in the chain with medical evidence. This is a harder claim and depends on the specific history.

Tinnitus is one of the most commonly service-connected conditions, and it produces a short but real secondary list. Constant ringing disrupts sleep, and chronic sleep loss feeds anxiety and depression. Those are the conditions most often granted as secondary to tinnitus, rated under the mental-health formula. Migraines secondary to tinnitus are claimed often. The medical link is weaker, and a nexus opinion has to explain it in the veteran's own history rather than assert it.

TBI, rated under DC 8045, has 1 of the longest secondary lists in the schedule. The regulation itself says to rate the physical, emotional and cognitive residuals separately where they have their own diagnoses. Post-traumatic headache rated as migraine under DC 8100 is the most common. Others with solid support: sleep disorders, depression and anxiety, vertigo and balance problems, seizure disorders, and hearing loss or tinnitus from the same blast or impact.

Migraines sit on both sides of this list. As a primary condition they can lead to depression and sleep disturbance. As a secondary condition they most often follow TBI, cervical spine injuries, and, through medication or stress, PTSD. DC 8100 rates them by how often prostrating attacks occur, so a headache log is evidence the DBQ can use more here than for almost any other condition.

These are the secondary chains with the strongest medical evidence, because the complications are part of how the diseases are defined.

Type 2 diabetes mellitus (DC 7913 in 38 CFR 4.119) damages small blood vessels and nerves over time. The established complications: peripheral neuropathy in the feet and hands, diabetic retinopathy and other eye disease, kidney disease (nephropathy), coronary artery disease and stroke, erectile dysfunction, and hypertension. The diabetes code itself tells raters to "evaluate compensable complications of diabetes separately." Veterans with diabetes presumed from Agent Orange or other exposures use this chain more than anyone.

Hypertension (DC 7101 in 38 CFR 4.104) leads to heart disease, stroke and kidney disease, and heart disease from hypertension is VA's own example of a secondary claim. The reverse is also true: kidney disease can cause hypertension.

Heart disease can lead to depression, and to sleep apnea in the aggravation direction, where untreated apnea worsens heart failure and heart failure worsens apnea. Records that show which came first matter here.

A side effect of a drug prescribed for a service-connected condition is a secondary condition under 3.310(a). The drug is the link. These are the pairings with the clearest pharmacology. In each case the medication list from VA or your pharmacy is the evidence of the link:

Source: prescribing information for each drug class; confirm the side effect against the label of the specific medication in your records.

Two rules apply. The medication must be prescribed for a service-connected condition, and the side effect must be diagnosed, not just listed on the package insert. A treatment note in which the prescribing provider records the link at the time is stronger than a letter written 3 years later.

VA does not add ratings. Under 38 CFR 4.25, it lists them from most to least severe and combines them with a table, then rounds to the nearest 10 (values ending in 5 round up). The regulation's own example: 50% and 30% combine to 65, which becomes 70.

A worked example with 2026 rates (effective December 1, 2025):

Source: https://www.va.gov/disability/compensation-rates/veteran-rates/ and https://www.va.gov/disability/compensation-rates/special-monthly-compensation-rates/, effective December 1, 2025.

Notice the third row. A 10% rating added to a 75 changes nothing after rounding. That is the frustrating side of VA math, and why the order and size of your ratings matter. Our VA math calculator runs any set of ratings, and understanding VA disability ratings explains why the table works this way. Dependents raise every rate from 30% up; see the 2026 rates page.

Will filing a secondary claim put my existing ratings at risk? A secondary claim asks VA to rate a new condition; it does not reopen the old ones. VA can schedule a re-exam on an existing rating under 38 CFR 3.327 when it expects the condition to improve. It does not do so for static conditions, ratings unchanged for 5 or more years, or veterans over 55. Ratings held 5, 10 and 20 years carry protections under 38 CFR 3.344, 3.957 and 3.951. Before any reduction, VA must send a proposed-reduction letter with 60 days to respond. The understanding VA disability ratings guide sets out each rule.

Secondary claims are decided on paper. The VA claim exam (C&P exam) examiner can confirm your diagnosis. But the link between conditions is a medical-opinion question, and VA examiners often answer it in 1 line. The medical opinion already in the file carries most of the weight.

1. A current diagnosis. Treatment records from VA or a private provider showing the secondary condition has been diagnosed, not just mentioned as a complaint.
2. Evidence of the primary. Your rating decision or the letter from VA that lists your service-connected conditions.
3. A nexus opinion. A doctor's written statement that it is "at least as likely as not" (a 50% or greater probability) that the service-connected condition caused or aggravated the secondary one. The reasoning and the medical literature behind it matter as much as the phrase. That phrase matches the benefit-of-the-doubt standard in 38 CFR 3.102: when the evidence is in approximate balance, VA resolves it in your favor.
4. A Disability Benefits Questionnaire (DBQ). VA publishes public DBQs your own provider can complete for most conditions. VA does not pay for them, but they put your evidence in the format the rater uses.
5. Baseline evidence for aggravation claims. Records showing how severe the condition was before the service-connected condition made it worse. Without a baseline, 3.310(b) says VA will not concede aggravation.
6. Lay statements. Your own statement and those of a spouse or coworker about when symptoms started and how they changed. Useful for timing; not a substitute for the medical opinion.

A secondary claim is filed on VA Form 21-526EZ, Application for Disability Compensation and Related Compensation Benefits, the same form used for any new condition. You can file it yourself or with a VA-accredited representative; a Veterans Service Organization (VSO) representative's help is free. If VA denied the secondary condition before, a Supplemental Claim on VA Form 20-0995 with new and relevant evidence, usually a nexus letter, reopens it. The gathering new evidence guide covers what counts as new and relevant, and C&P exam preparation covers what to expect at the exam.

Watch out: There is no deadline, but there is a cost to waiting. VA's effective date for a new condition is the later of the date it receives your claim or the date the condition began. An intent to file holds your date while you collect the nexus letter, and filing online sets it the moment you start the form.

State benefits do not depend on whether a rating is primary or secondary; they depend on the combined percentage. A secondary grant that moves you from 70% to 80%, or from 90% to 100%, can cross a state threshold. Examples: a property-tax exemption, a disabled-veteran plate, free hunting and fishing licenses or a dependent tuition waiver. Many of the largest state benefits require 100% or Permanent and Total (P&T) status. That is why a well-supported secondary claim can be worth more than its monthly dollar amount. Find your state's thresholds in the state veteran benefits finder.