  We present that including the hadron loop effects could help us to understand
the spectrum of the heavier charmonium-like states and their decays
simultaneously. The observed states could be represented by the poles on the
complex energy plane. By coupling to the opened thresholds, the pole positions
are shifted from the bare states predicted in the quenched potential model to
the complex energy plane. The pole masses are generally pulled down from the
bare masses and the open-charm decay widths are related to the imaginary parts
of the pole positions. Moreover, we also analyze the pole trajectory of the
$\chi_{c1}(2P)$ state while the quark pair production rate from the vacuum
changes in its uncertainty region, which indicates that the enigmatic X(3872)
state may be regarded as a $1^{++}$ $c\bar{c}$ charmonium-dominated state
dressed by the hadron loops as the others.
