Caluza Triangle defines what is necessary for service connection.

Caluz Triangle

This HAS to be MEDICALLY Documented in your records:

  1. Current Diagnosis.   (No diagnosis, no Service Connection.)
  2. In Service Event or Aggravation.
  3. Nexus (link- cause and effect- connection) or Doctor’s Statement close to: “The Veteran’s (current diagnosis) is at least as likely due to x Event in military service.”

This is also known as the “Hickson Elements” for a later case. Why you need to know:  If all 3 of these things are not documented in your medical and service records, then you will need to obtain this documentation before getting service-connected.  This applies if you applied last week or ten years ago.

Note:  Secondary Service Connection and Presumptive’s are a little easier.  Suppose you have a diagnosis, and a doctor says that your diagnosis is at least as likely as not a result of your (service-connected condition). In that case, you need not AGAIN establish an in-service event or aggravation.    A presumptive Service connection means if you meet the applicable criteria, then your condition is “presumed” to be caused by military service.  You are still gonna need a current diagnosis, but you may get a by on the nexus if you meet the requisite criteria for presumptive conditions.

Hickson Elements –In order to establish service connection for the claimed disorder, there must be:
1. medical evidence of a current disability;
2. medical, or in certain circumstances, lay evidence of the incurrence or aggravation of a disease or injury in service or during the presumptive period; and
3. medical evidence of a nexus between the claimed in-service disease or injury and the current disability. Hickson v. West, 12 Vet. App. 247, 253 (1999).

More on Caluza Triangle from member Broncovet: