  We study the problem of spin diffusion in magnetic systems without long-range
order. We discuss the example of the 1D spin chain. For the system described by
the Heisenberg Hamiltonian we show that there are no diffusive excitations.
However, the addition of an arbitrarily small dissipation term, such as the
spin-phonon interaction leads to diffusive excitations in the long time limit.
For those excitations we estimate the spin-diffusion coefficient by means of
the renormalisation group analysis.
