diff --git a/src/controllers/reference_range.ts b/src/controllers/reference_range.ts
index 6e5a5d5..63a3631 100644
--- a/src/controllers/reference_range.ts
+++ b/src/controllers/reference_range.ts
@@ -81,10 +81,10 @@ export class ReferenceRangeController {
 		try {
 			const schema = Joi.object().keys({
 				gender: Joi.string().valid("male", "female").required().label("Gender"),
-				age_range_min: Joi.number().integer().min(0).default(0).required().label("Age Range Min (days)"),
-				age_range_max: Joi.number().integer().min(0).default(36500).required().label("Age Range Max (days)"),
-				value_min: Joi.number().required().label("Value Min"),
-				value_max: Joi.number().required().label("Value Max"),
+				age_range_min: Joi.string().max(256).default("0 day").required().label("Age Range Min"),
+				age_range_max: Joi.string().max(256).default("999 years").required().label("Age Range Max"),
+				value_min: Joi.string().max(256).required().label("Value Min"),
+				value_max: Joi.string().max(256).required().label("Value Max"),
 				status: Joi.string().required().label("Status"),
 			});
 
@@ -92,8 +92,8 @@ export class ReferenceRangeController {
 
 			let referenceRange = new ReferenceRange();
 			referenceRange.gender = param.gender;
-			referenceRange.age_range_min = param.age_range_min;
-			referenceRange.age_range_max = param.age_range_max;
+			referenceRange.age_range_min = param.age_range_min || "0 day";
+			referenceRange.age_range_max = param.age_range_max || "999 years";
 			referenceRange.value_min = param.value_min;
 			referenceRange.value_max = param.value_max;
 			referenceRange.status = param.status;
@@ -155,10 +155,10 @@ export class ReferenceRangeController {
 			const schema = Joi.object().keys({
 				id: Joi.string().uuid().required().label("Reference Range ID"),
 				gender: Joi.string().valid("male", "female").required().label("Gender"),
-				age_range_min: Joi.number().integer().min(0).default(0).required().label("Age Range Min (days)"),
-				age_range_max: Joi.number().integer().min(0).default(36500).required().label("Age Range Max (days)"),
-				value_min: Joi.number().required().label("Value Min"),
-				value_max: Joi.number().required().label("Value Max"),
+				age_range_min: Joi.string().max(256).default("0 day").required().label("Age Range Min"),
+				age_range_max: Joi.string().max(256).default("999 years").required().label("Age Range Max"),
+				value_min: Joi.string().max(256).required().label("Value Min"),
+				value_max: Joi.string().max(256).required().label("Value Max"),
 				status: Joi.string().required().label("Status"),
 			});
 
@@ -169,8 +169,8 @@ export class ReferenceRangeController {
 			if (!referenceRange) throw { message: "Reference Range " + Language.lang.failed_not_found };
 
 			referenceRange.gender = param.gender;
-			referenceRange.age_range_min = param.age_range_min
-			referenceRange.age_range_max = param.age_range_max;
+			referenceRange.age_range_min = param.age_range_min || "0 day";
+			referenceRange.age_range_max = param.age_range_max || "999 years";
 			referenceRange.value_min = param.value_min;
 			referenceRange.value_max = param.value_max;
 			referenceRange.status = param.status;
diff --git a/src/swagger/builder.js b/src/swagger/builder.js
index 305ea53..7ecf975 100644
--- a/src/swagger/builder.js
+++ b/src/swagger/builder.js
@@ -165,10 +165,10 @@ const doc = {
             },
             referenceRange: {
                 $gender: { "@enum": ["male", "female"] },
-                $age_range_min: "0 | (days)",
-                $age_range_max: "20 | (days)",
-                $value_min: "13.7",
-                $value_max: "17.5",
+                $age_range_min: "0 day",
+                $age_range_max: "20 years",
+                $value_min: "0",
+                $value_max: "20",
                 $status: { "@enum": ["Y", "N"] }
             },
             queueMonitoring: {