Thread: Doubly linked list is only creating one node.

Hey guys, trying to create a program which add/store records of patients to a node using doubly linked list. When the program executes, I'm only able to create one record. The program doesn't allow me add anymore patient and when I tried to display the record the program output different characters to the screen instead of the record.

Code:

#define STRING_MAX 40


typedef struct Patient{
    char patientName[STRING_MAX];
    int patientAge;
    int patientRegion;
    struct Patient *prev;
    struct Patient *next;
}Patient;

struct Patient *head, *tail = NULL;
struct Patient *current = NULL;


void addPatient()
{   char *patientName;
    int patientAge;
    int patientRegion;


    struct Patient *patient = (Patient *)malloc(sizeof(Patient));
    strncpy(patient->patientName,patientName,STRING_MAX);
    patient->patientAge = patientAge;
    patient->patientRegion = patientRegion;
    patient->prev = NULL;
    patient->next = NULL;


    if(head == NULL){//if head node is null, then get user input to create a record
        printf("Enter patient Name: \n");
        scanf("%s", patientName);
        printf("Enter patient Age: \n");
        scanf("%d", &patientAge);
        printf("Enter patient Region: \n");
        scanf("%d", &patientRegion);


        while(patientRegion > 10) //If the region is greater than ten, prompt user to enter a number less than 10
        {
            printf("Invalid region\n");
            printf("Please enter region between (1 - 10): ");
            scanf("%d", &patientRegion);
        }
        head = patient;
        return;
    }
}

void displayPatient(){
    struct Patient *current = head;
    if(head == NULL) {
        printf("\nList is empty\n\n");
        return;
    }


    printf("Patient Records: \n");
    while(current != NULL) {
        printf("%s", current->patientName);
        printf("%d", current->patientAge);
        printf("%d", current->patientRegion);


        current = current->next;
    }
}