Uniform asymptotic approximations are obtained for the Whittaker’s confluent hypergeometric functions
are real. Three cases are considered, and when taken together, result in approximations which are valid for
, and also for
. The results are obtained by an application of general asymptotic theories for differential equations either having a coalescing turning point and double pole with complex exponent, or a fixed simple turning point. The resulting approximations achieve a uniform reduction of free variables from three to two, and involve either modified Bessel functions or Airy functions. Explicit error bounds are available for all the approximations.